Jordan Spieth needed an incredible stroke of luck to sneak under the cut-line during Friday's weather-interrupted second round of The Players Championship.

On a day when the two best performers from round one – Chad Ramey and Collin Morikawa – both shot over par, the top story was the unlikely eagle on the final hole from Spieth to go from two over to even par.

Likely needing a birdie to make the cut, Spieth sliced his drive towards the water, but instead of going in and ending his week, it struck a spectator's knee and ricocheted back into the fairway.

He went on to put his second shot on the par-five ninth hole into the greenside rough, where he would chip in for eagle.

After the round, Spieth said he was "trying to get that guy's information and see literally whatever he wants this weekend because everything from here on out is because it hit him".

Meanwhile, still with plenty of holes to play after weather forced the afternoon starters to wrap up early, South Africa's Christiaan Bezuidenhout (through 14) and Canada's Adam Svensson (through 11) sit two strokes clear of the field at eight under.

Morikawa could not replicate his opening 65, sitting at one over for his round through 11 holes and six under overall, tied with fellow American Ben Griffin and Australia's Min Woo Lee (through 15) in third.

World number two Scottie Scheffler (through 10) is with Taylor Pendrith as the only players at five under, while Jason Day and Viktor Hovland headline the final group in the top 10 at four under.

The field lost world number one Jon Rahm as he withdrew due to illness an hour before teeing off, while Rory McIlroy is almost certainly going to miss the cut at six over with eight holes to play.

Jon Rahm's phenomenal front nine earned him a share of the lead with Davis Thompson after the third round of The American Express in California on Saturday.

World number four Rahm shot 30 in his first nine holes on the Stadium Course at La Quinta Country Club, including four birdies and an eagle on the fifth to claim the lead by three strokes from Thompson, who had gone into the third day ahead by two.

Rahm launched an aggressive second shot on the par-five fifth, setting up his eagle putt from the edge of the green.

The Spaniard cooled off after another birdie on the 12th to finish the day with a seven-under-par 65, having carded back-to-back 64s on the opening two days.

Thompson shot a five-under-par 67 on the Stadium Course, making an up-and-down birdie on the 16th hole to re-claim a share of the lead.

Rahm and Thompson are joint top on 23-under overall, four strokes ahead of J.T. Poston and Christiaan Bezuidenhout.

Bezuidenhout enjoyed a scintillating 10-under round on the Nicklaus Tournament Course to surge up the leaderboard, making six birdies on his back nine.

But the round of the day went to Dylan Wu, whose 11-under-par 61 matched Will Zalatoris' Nicklaus Tournament Course record. 

The American had a run of six straight birdies on his front nine and would have broken the course record if not for a par on the 18th.

Wu, at 17-under, is part of a six-player group that includes world number two Scottie Scheffler. 

Davis Riley produced a bogey-free opening round to claim a share of the lead alongside Will Gordon after the opening day of the Sanderson Farms Championship on Thursday.

Mississippi-native Riley carded a six-under-par 66 including four birdies in his first seven holes to set the pace at the Country Club of Jackson.

Riley he also holed an 18-foot putt for birdie on the 17th, backing up his birdie on the 16th for a strong opening round.

Gordon, who was among the last to finish on the opening day, came in strong with three birdies in his final five holes. He sunk a 23-foot birdie putt on the ninth.

Seven players are tied at five-under, including tour rookie Brandon Matthews who finished his round with back-to-back birdies to card 67.

Matthews is tied with Andrew Putnam, Kevin Yu, Mark Hubbard, Thomas Detry, Trevor Cone and Christiaan Bezuidenhout, the latter fresh from his Presidents Cup debut.

Among the day's highlights were aces on the fourth hole to Brandon Wu, who is three-under-overall, and M.J. Daffue, who had just double bogeyed the par-five third hole.

Reigning champion Sam Burns carded a bogey-free two-under-par 70, while one of the pre-tournament favourites Denny McCarthy is a further stroke behind after birdieing his final two holes.

Sahith Theegala (one over), Russell Henley (two over) and J.T. Poston (four over) struggled on the opening day, with the latter carding four bogeys and one double bogey in the par-four 12th.

J.T. Poston claimed his second PGA Tour win on Sunday, holding on to win the John Deere Classic at TPC Deere Run.

The 29-year-old posted a two-under 69 in the fourth and final round to finish on 21-under for the tournament, three shots clear of Emiliano Grillo and the fast-finishing Christiaan Bezuidenhout, tied for second at 18-under.

As well as qualifying for The Open Championship, Poston becomes the first player since David Frost in 1992 to go wire-to-wire at the John Deere Classic and only the third in the tournament's history along with Scott Hoch, who achieved the feat in 1980.

Poston revealed it was not easy to remove the possibility of that achievement from his mind following his round, but with his last win coming at the 2019 Wyndham Championship, believes it is a boost for his confidence.

"It is hard," he told CBS. "I mean, wire-to-wire, having the lead for that long, it's just hard not to think about it and think about that finish line.

"I tried to stick to the game plan. We got off to a great start and then, kind of started to try and give some back, but I hit a lot of good shots down the stretch.

"I was just trying to breathe. I think there were a lot of nerves, more than the first few days. I was just trying to battle through them and I think, after this week, knowing I can play with those nerves. I can still win, I can still shoot a solid score considering the pressure and trying to win out here."

Poston started strongly, opening the round with consecutive birdies on each of the first three holes, but his momentum was halted with bogeys on the fifth and sixth holes.

His round stabilised on the back nine, however, with a birdie on the par-five 17th effectively securing the tournament.

Poston was able to see off Grillo and Bezuidenhout, who claimed three birdies over the closing five holes, with Christopher Gotterup and Scott Stallings finishing a further stroke back on 17-under.

Phil Mickelson and Brooks Koepka both shot 70 Saturday to set up a mouth-watering final pairing at the US PGA Championship. 

At seven under par for the tournament, Mickelson holds a one-stroke lead over his countryman entering the final round at Kiawah Island's Ocean Course after saving par on 18 while Koepka bogeyed the last. 

The 50-year-old Mickelson is the fourth player aged 50 or older to lead a major after three rounds in the modern era, which began in 1934. 

The others were Tom Watson at the 2009 Open Championship, Greg Norman at the 2008 Open, and Julius Boros at the 1973 US Open -- none of whom ended up holding on for the win. 

Mickelson has been resilient this week in South Carolina, though, steadying himself Saturday after going bogey-double bogey on 12 and 13 to make par on the final five holes. 

While Mickelson's resurgence has excited the fans, Koepka remains a model of consistency at the PGA.

He has finished at least tied for fourth in 12 of the last 13 rounds at the major, and he could become the first player to win the same major three times in a four-year stretch since Watson won the Open in 1980, 1982 and 1983.

Mickelson will be shooting for his sixth major title and first since the 2013 Open, while Koepka seeks his fifth. 

Louis Oosthuizen, who shared the lead with Mickelson entering play Saturday, managed just three birdies on the day on the way to an even-par 72 that left him five under for the tournament. 

American Kevin Streelman (70) is at four under, while Oosthuizen's South African countrymen Branden Grace and Christiaan Bezuidenhout are at three under after even-par rounds of their own. 

Bryson DeChambeau (71) was unable to gain ground on the leaders and enters Sunday five back of Mickelson along with Gary Woodland (72) and Joaquin Niemann (71). 

Jordan Spieth matched Billy Horschel for the low round of the day with a 68, and he sits at even par for the tournament along with Rickie Fowler (69) and Keegan Bradley (72).

Reigning Masters champion Hideki Matsuyama fell from contention with a 76, putting him at one over with the likes of Shane Lowry (73), Padraig Harrington (73) and Ian Poulter (73).