Cameroon captain Vincent Aboubakar led from the front with a clinical double as the Africa Cup of Nations hosts swept to a 4-1 win over Ethiopia.

At the Olembe Stadium in Yaounde, Aboubakar and Karl Toko Ekambi feasted on generous defending to make it two wins from two for Cameroon. For Aboubakar, this was his second double in AFCON so far, after also scoring twice in an opening win over Burkina Faso.

Ethiopia stunned the home crowd with a fourth-minute opener, Dawa Hotessa tucking in from close range after some dismal defending. But there was a near-immediate response, Cameroon levelling with a fine header from Toko Ekambi in the eighth minute.

Aboubakar saw a 25-yard shot repelled by Ethiopia goalkeeper Teklemariam Shanko in the lead-up, but Collins Fai collected the loose ball wide on the right and sent in a fine cross for Toko Ekambi to finish clinically at the far post.

It was another cross from Fai that caused chaos in the Ethiopia penalty area and allowed the hosts to edge 2-1 ahead in the 53rd minute. The delivery came from the right once more, and Aboubakar powered his header down into the ground and into the back of the net.

Aboubakar's second arrived two minutes later, the striker tucking in Nicolas Moumi Ngamaleu's low cross from the edge of the six-yard box. Toko Ekambi, who also hit the post with a header, completed his own double with a powerful low shot in the 67th minute as Ethiopia's defence stood off, unable to handle Cameroon's quality once more, the story of the game encapsulated.

A "detailed analysis" of the controversial ending to last month's Abu Dhabi Grand Prix has started, the Federation Internationale de l'Automobile (FIA) has confirmed.

Seven-time champion Lewis Hamilton was denied a record-breaking eighth title when he was beaten by Red Bull's Max Verstappen on the final lap of the season-ending grand prix on December 12.

Mercedes were furious with how race rules were applied in a safety-car situation and challenged the result, believing Hamilton was unfairly prevented from winning the race and the championship when Verstappen passed him with only a few corners remaining.

The German constructors launched two challenges that were both rejected by the FIA, with Mercedes giving notice of an intention to appeal. However, the team eventually decide not to proceed down that route following discussions with F1 and the FIA.

On Thursday, the FIA released a statement via Twitter outlining the next steps in their analysis of the situation, saying: "Following the decision of the World Motor Sport Council in Paris on 15 December 2021, the FIA administration, under the leadership Mohammed Ben Sulayem, has started the detailed analysis of the events of the last Formula 1 Abu Dhabi Grand Prix.

"The FIA President launched a consultation with all F1 teams on various issues, including this one.

"On January 19, an item on the agenda of the Sporting Advisory Committee will be dedicated to the use of the Safety Car. The following stage will be a shared discussion with all F1 drivers.

"The outcome of the detailed analysis will be presented to the F1 Commission in February and final decisions will be announced at the World Motor Sport Council in Bahrain on 18 March."

There has been recent speculation since the end of the season that Hamilton could retire from motor racing, with the 36-year-old and his team left distraught by the outcome, and reports suggest that the Briton is waiting to see the outcome of an inquiry.

Damian Lillard will be out for at least six weeks after the Portland Trail Blazers star underwent abdominal surgery.

The point guard had been increasingly troubled by a long-standing injury and decided to take action after playing in a 139-106 thrashing at the hands of the Los Angeles Lakers on New Year’s Eve.

Portland on Thursday confirmed Lillard had been operated on by Dr William C. Meyers at The Vincera Institute in Philadelphia to "repair a core injury causing chronic abdominal pain."

The Trail Blazers are 10th in the Western Conference at 16-24 and must now do without six-time NBA All-Star Lillard for at least a month and a half.

The 31-year-old told Blazers.com: "Last year it was pretty bad.

"Going from that long season, playing a few months without Nurk [Jusuf Nurkic] and without CJ [McCollum] and having to play more minutes, then coming off a short summer after the bubble season where I was hurt in the bubble and going into last year and then not having a break after last year just training for the Olympics, going to the Olympics.

"At the Olympics it was as bad as it'’s been and I was just like 'Man, this is a real issue.' There was really no time for me to do it. I just decided to rest.

"I took like 30 days where I didn't do nothing and I felt a lot better coming into camp. I felt fresh, I had been working out and stuff, it hadn't been giving me any trouble because I was coming off such a long break.

"And then the second that we started camp I felt good the first day, day and a half. Then I started to feel it again and I was like 'Man, I thought the rest would help for a longer period of time.' But it didn't."

Lillard added: "I know [surgery] is ultimately going to be what's best for the team, too. I'd rather be selfish for the team, what I see for our organisation and where I want it to go.

"It makes no sense to keep doing it the way we was doing it. It's like, alright, take a step back to take how many steps forward. It's just what had to happen."

Key man Lillard is averaging 24 points, 4.1 rebounds and 7.3 assists from 29 games this season

MotoGP legend Valentino Rossi will switch to four-wheel racing to drive for Team WRT in the GT World Championship.

Rossi ended his incredible MotoGP career last November, finishing 10th in his final race at the Valencia Grand Prix.

The Italian icon, a seven-time world champion in the premier class, hung up his gloves at the age of 42.

But Rossi has agreed to take on a new racing challenge, having tested with Team WRT in Valencia last month.

He will be an official Audi sport driver, taking part in a 10-round competition striving to win the Endurance Cup and Sprint Cup.

Rossi said: "I am delighted to join Team WRT for a full Fanatec GT World Challenge Europe powered by AWS programme.

"Everybody knows that I have always been a great car racing fan and that I have always been interested in racing on four wheels once my MotoGP career would come to an end.

"Now I am completely available to devote myself to a car racing programme at a high level and with the right professional approach.

"Team WRT is the perfect fit I was looking for and I am anxious to start this new adventure in the Fanatec GT World Challenge Europe powered by AWS with them."

Eddie Hearn expects Anthony Joshua to announce who his new trainer will be either at the end of this month or early in February.

Joshua decided to shake things up after losing his WBA (Super), IBF, WBO and IBO heavyweight titles to Oleksandr Usyk at Tottenham Hotspur Stadium last September.

Eddy Reynoso, Virgil Hunter and Anthony Wilson are among the trainers Joshua could recruit, while Floyd Mayweather has been giving the Briton advice ahead of an eagerly anticipated rematch with Usyk that has not yet been confirmed.

Hearn, Joshua's promoter, told iFL TV: "I think AJ will make an announcement when camp starts, which I guess will be end of January, early February.

"He's worked hard to get it right. A lot of people have said, 'do you think it's risky to bring in a new trainer?'

"I flip that and say, 'do you think it's risky to not be comfortable with your set-up or your surroundings?'"

Hearn says having a new face in Joshua's corner will not mean there is no role to play for his long-time trainer Robert McCracken.

"He'll always be involved in some way," Hearn said of McCracken.

"He's more than just a trainer to Anthony Joshua... he's a mentor, an advisor.

"Those two will always talk – in what capacity, I don't know. I'll leave that to AJ to announce. But there will certainly be additions to the training team."

Joshua was outclassed by Usyk, suffering the second defeat of his professional career after he was also surprisingly dethroned by Andy Ruiz Jr in 2019.

Novak Djokovic put the Australian Open at risk and has made other participants "look like fools" by turning up for the tournament unvaccinated, according to Stefanos Tsitsipas.

World number one Djokovic was paired with Miomir Kecmanovic in Thursday's draw for the opening round, but it remains uncertain whether he will even take part in the first grand slam of the year.

The Serbian was last week given a medical exemption to enter Australia, despite not being vaccinated, only for border officials to block it upon his arrival.

Djokovic was detained for four days while waiting to appeal the case on Monday, which went in his favour at Melbourne Circuit Court.

He has since started training ahead of the Australian Open, which begins next Monday, though immigration minister Alex Hawke may yet cancel his visa for a second time.

The 34-year-old is also being investigated for breaching isolation rules in December after testing positive for COVID-19.

And as a decision regarding whether he can stay in Australia and defend his title is dragged out, Tsitsipas has become the highest-profile tennis figure to criticise Djokovic for his conduct.

"He has been playing by his own rules," world number four Tsitsipas told Indian outlet WION.

"No one would have thought: 'I can come to Australia unvaccinated and not have to follow the protocols they gave me'.

"For Novak it worked another way. It takes a lot of daring to do. Putting a Grand Slam at risk – I don't think many players would do that."

Tsitsipas, who was defeated by Djokovic in last year's French Open final, added: "There are two ways to look at it.

"One way is that almost every single player has been vaccinated and did what they had to do in order to come and play in Australia.

"We have all followed the protocols to come and compete in Australia and been very disciplined in that.

"It seems like not everyone is playing by the rules of how Tennis Australia and some governments have been putting things.

"A very small minority chose to follow their own way. It makes the majority look like they are all fools."

Djokovic has spent the past four days training on court in preparation for the Australian Open, which he has won a record nine times, including in each of the last three years.

But weighing in on the debate on Thursday, Australian deputy prime minister Barnaby Joyce said the 20-time grand slam winner must "abide by the rules" if he is to remain in the country.

"You have to be frank – the vast majority of Australians said they didn't like the idea that another individual, whether they're a tennis player or the king of Spain or the queen of England, can come up here and have a different set of rules to what everybody else has to deal with," Joyce said.

"Let's see where it goes from here… I've made my views clear. I might not agree with the fact that I have to be tested to go from New South Wales into Queensland but I do [it’. Why? Because that is the law.

"He is no better. He is still a child of God like the rest of us, isn't he? So he has got to abide by the laws."

Africa Cup of Nations chiefs have launched an investigation into why referee Janny Sikazwe blew for full-time twice before 90 minutes was up in Tunisia's match against Mali.

Tunisia head coach Mondher Kebaier described Sikazwe's officiating of Wednesday's game as "inexplicable".

Mali were leading the Group F match 1-0 through a Ibrahima Kone penalty when the Zambian official blew for full-time in the 85th minute.

Kebaier realised his error and play resumed for another four minutes, during which time Mali forward El Bilal Toure was dismissed, before blowing again with 13 seconds of the 90 minutes to go.

That was despite there being a number of stoppages in the second half, including a couple of lengthy VAR checks for Kone's penalty and one that Wahbi Khazri missed for Tunisia.

Tunisia officials stormed onto the field to protest and later refused to send their team back to the field when it was decided to play on for the final stages.

Now the Confederation of African Football (CAF) has confirmed it is probing the circumstances of the farcical and controversial scenes, which grabbed global attention.

It has been reported that Sikazwe was taken to hospital after the game, with the effects of heatstroke and dehydration having caused him to lose focus.

"In relation to the TotalEnergies Africa Cup of Nations match between Tunisia and Mali played in Limbe on 12 January 2022, CAF is gathering all the necessary reports from the officials at the match," a CAF statement read.

"CAF is forwarding these documents to the competent bodies of CAF. At this stage, CAF is not in a position to make further comment until the responsible bodies indicate the way forward."

Daria Kasatkina reached her second semi-final in as many weeks with a straight-sets victory over Garbine Muguruza at the Sydney Tennis Classic on Wednesday.

The world number 26, who was defeated by Amanda Anisimova in the Melbourne Summer Set 2 semi-finals last week, beat second seed Muguruza 6-4 6-4.

Kasatkina held throughout the opening set, landing 67 per cent of her first serves, and saw the job through in the second despite a couple of early breaks for Muguruza.

It is the Russian's first win over a top-five opponent since beating Caroline Wozniacki at the 2018 French Open.

She will now face fifth seed Paula Badosa, who saw off Olympic gold medallist Belinda Bencic 7-6 (8-6) 3-6 6-3 in an entertaining match lasting two hours and 35 minutes.

The other semi-final in Sydney will be contested between Anett Kontaveit and Barbora Krejcikova, who advanced past Ons Jabeur and Caroline Garcia respectively.

Krejcikova proved far too strong for Garcia, prevailing 6-0 6-2 in 70 minutes, while Kontaveit was in action for just 43 minutes before being handed a walkover win in her match.

Jabeur had targeted "payback" against Kontaveit after her quarter-final opponent pipped her to the final WTA Finals spot in November, but injury cost her the chance to do so.

Having lost the first set 6-4, Jabeur – who eliminated Petra Kvitova in the previous round – felt unable to continue due to a lower back injury.

At the Adelaide International 2, three of the five Americans in action made it through to the semi-finals.

Alison Riske's clash with compatriot Madison Brengle ended early due to the latter retiring with the first set level at 3-3. Tamara Zidansek awaits Riske after beating Lauren Davis 7-6 (7-4) 7-6 (9-7).

Coco Gauff and Madison Keys will meet in the other semi-final, meanwhile, following victories over Ana Konjuh and Ludmilla Samsonova in two and three sets respectively.

Andy Murray strode through to the semi-finals at the Sydney Classic after opponent David Goffin was forced to retire with an injury.

Murray won the opening set 6-2 before eighth seed Goffin, who had been receiving treatment on his knee, determined he could no longer continue.

It is the first time the 34-year-old Murray has reached a semi-final on the ATP Tour since winning the European Open title in October 2019.

Though not ideal circumstances, Murray will at least be glad of the extra rest after his three-hour encounter with world number 23 Nikoloz Basilashvili in the second round. The Scot has also been drawn to play Basilashvili in the first round of the Australian Open.

Murray will face Reilly Opelka in the last four in Sydney after the American beat compatriot Brandon Nakashima 7-6 (7-4) 6-2 to advance.

Top seed Aslan Karatsev was made to work for his win against Italy's Lorenzo Sonego but secured a 6-3 3-6 6-2 victory to book his semi-final place against Briton Dan Evans, who defeated American Maxime Cressy 6-4 7-6 (7-5). Cressy reached the final of the Melbourne Summer Set tournament last week.

At the Adelaide International 2 event, third seed Karen Khachanov tumbled out after losing in straight sets to Arthur Rinderknech, the Frenchman coming through a 7-6 (9-7) 7-5 winner.

Rinderknech will face compatriot Corentin Moutet in the semi-finals after the qualifier overcame Thiago Monteiro 6-4 6-4.

Fourth seed Marin Cilic battled to beat American Tommy Paul 6-4 2-6 6-3, and a test awaits against Thanasi Kokkinakis who defeated fellow Australian Aleksandar Vukic 6-7 (5-7) 6-3 6-2.

Gabon coach Patrice Neveu has tested positive for COVID-19 and missed training on Thursday as captain Pierre-Emerick Aubameyang returned from isolation with a rallying call.

Neveu's team started their Africa Cup of Nations campaign with a 1-0 win over Comoros on Monday, but the coach appears certain to be absent for their second game on Friday when Ghana provide the opposition.

The Gabonese Football Federation confirmed Neveu's positive test result and stated training was led by assistant coach Anicet Yala, who himself tested positive on arrival in Cameroon last week.

Arsenal striker Aubameyang and Monaco midfielder Mario Lemina also returned positive results before the tournament began, but both are back on the training pitch and could be involved against Ghana.

Aubameyang said he had been able to train on an exercise bike and treadmill in his hotel room to keep up a basic level of fitness.

"Staying locked up is not easy," he said. "So we're happy to be back in training and in the squad."

Aubameyang contended it was too early to feel in any way serene about Gabon's progress in the competition and insisted he and his team-mates must stay focused as Ghana await them.

"I won't say serene, but it certainly feels good to start the competition with a victory," said Aubameyang, quoted on the Gabon team website. "After that, you shouldn't think that you won the [Cup of Nations] either.

"We are going to play a very tough opponent who want to win the game, so we will have to be serious as we were in the first game and I know that we will have our chances.

"I was already very happy that the guys did the job in the first game, we are all proud of them. Now it's up to me to level up and bring everything I can to the group."

The Cup of Nations was expected to provide welcome respite for Aubameyang after strife at club level.

His Arsenal future has become clouded by uncertainty after he was stripped of the club captaincy and dropped by manager Mikel Arteta following a disciplinary breach.

James Harden is excited by what could be as he along with team-mates Kevin Durant and Kyrie Irving combined to score 61 points in the Brooklyn Nets' 138-112 victory against the Chicago Bulls on Wednesday.

Harden managed a double-double of 25 points and a season-high 16 assists, while Durant scored a game-high 27 points to lead the Nets to a comfortable victory at United Center.

Kyrie Irving, who can only play on the road due to COVID-19 vaccine laws in New York, added nine points in his third game back for the Nets.

Speaking after the victory, which took the Nets to a 26-14 record for the season, Harden was asked about his on-court relationship with Durant and Irving.

"We're that good," Harden emphasised. "We have a chance to be that good. We just haven't had enough of it. Last year I think we had 15 games maybe together, and this year only two.

"It felt good tonight on both ends of the ball, to be locked in on the same page and, offensively, sharing the basketball and making each other better."

Durant also faced the media after another stellar showing, having now scored at least 25 points in 12 straight games, and the 11-time NBA All-Star made clear that he is not concerned with what people on the outside think of his team.

"We're trying to make no statements to the league," Durant said. "I mean, who cares what they think? We know what we bring to the table, and it's all about us. But I'm sure people were watching the game tonight."

Meanwhile, the Bulls became the first team in NBA history to win by 45+ points one day and then lose by 25+ the next, having beaten the Detroit Pistons 133-87 on Tuesday.

Coach Billy Donovan praised his team for a run that has seen them reach a 27-12 record so far, acknowledging that they were second best on the day, particularly in the third quarter when the Nets scored more than twice the number of points managed by the Bulls (39-19).

"I think you own it," Donovan said. "I think our guys have worked hard up to this point to be where we are in the standings, and with that there's a greater responsibility."

Joe Root has backed Chris Silverwood to stay on as head coach despite England's disappointing Ashes campaign

Silverwood's position, which he has held since being promoted from bowling coach in October 2019, is under growing pressure with England 3-0 down to Australia.

The 46-year-old presided over the Test defeats in Brisbane, Adelaide and Melbourne before missing last week's drawn fourth Test in Sydney because of COVID-19.

He is now back with the squad for the start of Friday's final Test in Hobart and Root is hopeful it will not be Silverwood's last at the helm.

Asked if he would like to see Silverwood remain in charge, Root said: "Yes, I would. 

"It was a difficult week for the group of players with him not being around and it must have been very difficult for him.

"But I think the performances we put in during the first three games, I feel we've let him and the coaches down to a degree. 

"We've not played anywhere near the level we're capable of. It's a chance to do that this week."

England have a three-Test series with West Indies to come after the Ashes and then host New Zealand, India and South Africa later in the year.

They suffered nine Test defeats in a logistically challenging 2021 that forced Silverwood to shuffle his resources due to COVID bubbles and player withdrawals.

And Root praised Silverwood for the manner in which he has gone about his business over the past 18 months or so.

"I think he's very calm, he has the respect of the guys and he's got a desperation to see everyone do well or up-skill the players as best he can," Root said. 

"He's had a very difficult time of it with the environments we've been living in, trying to manage winning matches with bubble environments away from home, and multi-format players trying to prepare for an Ashes and a World Cup. It's very difficult.

"For a long time we've not been able to put our best teams out because we've been constantly trying to make sure from a mental wellbeing point of view everyone is looked after properly, because of the schedule we've dealt with over two years."

Shaquille O'Neal has confirmed he has sold his stake in the Sacramento Kings in order to pursue other business interests.

The NBA legend, who spent the majority of a decorated career at the Los Angeles Lakers and the Miami Heat, became a partial owner of the Kings in 2013.

However, he confirmed on Twitter on Wednesday that he has been required to sell according the NBA rules due to his desire to begin a new business venture.

"As a result of a new business endeavour, I was required by NBA rules to sell my interest in the Sacramento Kings," the 49-year-old posted. 

"I want to thank the fans, the city of Sacramento, Vivek Ranadive and the entire Kings organization for our great partnership.

"I loved being an owner of such a forward-thinking organization and I hope to be back someday. Till we meet again..."

The four-time NBA champion made the announcement shortly before his former Lakers were beaten 125-116 by the Kings in Sacramento.