Kevin Na and Jason Kokrak rallied to win the QBE Shootout after birdieing 12 of their last 13 holes.

Na and Kokrak faced a three-shot deficit, but the American duo fought back in Naples, Florida, where they dazzled in Sunday's fourballs.

A combined 12-under-par 60 saw Na and Kokrak prevail by a stroke ahead of Billy Horschel and Sam Burns (61) at the unofficial PGA Tour team event.

Na and Kokrak, who also reeled off nine consecutive birdies, ended the week 33 under as overnight leaders Marc Leishman and Jason Day (65) finished third alongside defending champions Matt Kuchar and Harris English (62).

"We got off to a poor start," Na said. "We kept telling ourselves there are plenty of birdie holes out there. I started making some birdies and we got hot."

Jason Kokrak rallied with four consecutive birdies as a stellar back nine helped the American claim the Houston Open.

Kokrak carded a five-under-par 65 for an impressive two-shot victory and his third PGA Tour trophy at Memorial Park on Sunday.

The 36-year-old was two strokes behind with six holes to play before birdieing the 13th, 14th, 15th and 16th to trump countrymen Kevin Tway (68) and overnight leader Scottie Scheffler (69) to glory.

"Very blessed to be standing here," Kokrak said afterwards in Houston, where he found himself 10 shots adrift after two rounds.

Kokrak, who went 232 starts before his first PGA Tour victory, has now won three titles in his last 27 starts, dating back to October's CJ Cup.

"This win is very special. I was really struggling with my game at the beginning of this week," Kokrak added.

"But I was on the phone with my swing coach and worked on a few things and that worked really well. So, I have to thank him and my caddie, it was really tough at times out there."

Tway and Scheffler finished tied for second, while Kramer Hickok shot a final-round 69 to be outright fourth at seven under as Joel Dahmen (65) and Martin Trainer (70) ended the tournament a shot further back.

At the other end of the spectrum, former world number ones Adam Scott (73) and Jason Day (70) closed out the event at five over, two strokes better off than 2018 Masters champion Patrick Reed (77).

Jason Kokrak upstaged Jordan Spieth, outlasting the former world number one to lift the Charles Schwab Challenge trophy.

Spieth carried a one-stroke lead into the final round at Colonial Country Club, where the three-time major champion was looking to add to his 2016 triumph.

But Kokrak had other ideas and shot a 70 to prevail by two shots as Spieth faltered via a three-over-par 73 in Fort Worth, Texas on Sunday.

Kokrak mixed two birdies with three bogeys over the first seven holes, though a run of three birdies over a six-hole stretch from the eighth to the 13th fuelled the American.

The victory made Kokrak the first player over the age of 35 to win his first two PGA Tour titles in the same season since Italian Francesco Molinari achieved that feat – which included an Open Championship triumph – in 2018.

Spieth made a slow start behind three consecutive bogeys from the second to fourth holes before responding with birdies at the sixth and ninth, but he found water at the 18th, having bogeyed the 15th.

Kokrak – who finished 14 under – earned a second victory from his last 17 starts following the 36-year-old's success at the CJ Cup earlier this PGA Tour season.

Charley Hoffman (65), Patton Kizzire (67), Sebastian Munoz (68) and Ian Poulter (68) ended the tournament four shots off the pace in a tie for third.

Defending champion Collin Morikawa's bid for back-to-back titles resulted in a share of 14th position at five under after he posted a final-round 68.

Former world number one and 2013 U.S. Open champion Justin Rose (71) and Sergio Garcia (76) – the 2017 Masters champion and 2001 winner of this event – finished in a tie for 20th, 10 strokes behind Kokrak.

Jordan Spieth birdied his last hole to retain a one-stroke lead heading into the final round at the Charles Schwab Challenge.

Jason Kokrak had joined 2016 champion Spieth atop the leaderboard before the latter stepped up to birdie the 18th in the third round at Colonial Country Club on Saturday.

Former world number one Spieth signed for another four-under-par 66 to remain the player to beat ahead of Sunday's finale in Fort Worth, Texas.

Spieth, whose 40-hole bogey-free streak ended at the par-four fifth hole, is eyeing his second PGA Tour title of the season, having ended his four-year trophy drought via last month's Texas Open.

A three-time major champion, Spieth only dropped two shots as he finished with six birdies, including three across a flawless back nine to be 15 under through 54 holes.

Fellow American Kokrak stayed within a shot of Spieth courtesy of his third-round 66.

Sergio Garcia – the 2017 Masters champion and 2001 Charles Schwab Challenge winner – is five strokes off the pace following his two-under-par 68.

Ian Poulter (64) surged up the leaderboard, improving 26 positions to be tied for fourth at eight under alongside Sebastian Munoz (70).

Former world number one and 2013 U.S. Open champion Justin Rose (69) is 10 shots behind Spieth, defending champion Collin Morikawa is two strokes further back after his 72, while Justin Thomas (71) slipped to 46th – 14 shots adrift.

Jordan Spieth seized control of the Charles Schwab Challenge after claiming a one-shot lead at the half-way stage of the tournament, while Phil Mickelson failed to qualify for the weekend.

Former world number one and three-time major champion Spieth earned the outright lead thanks to a four-under-par 66 in Fort Worth, Texas on Friday.

Spieth entered the second round tied with 2017 Masters winners Sergio Garcia atop the standings by two strokes at Colonial Country Club.

Winner of the 2016 Charles Schwab Challenge, Spieth followed up his flawless 63 with another bogey-free round to move clear of the field after play was temporarily suspended due to inclement weather.

Spieth – who is the only bogey-free player through 36 holes at 11 under – holds his 13th second-round lead/co-lead on the PGA Tour – he is six-for-12 to date converting to victory.

Fellow American Jason Kokrak is second following his five-under-par 65, while Garcia (69), Sebastian Munoz (65) and Patton Kizzire (65) are two shots further back at eight under.

Defending champion Collin Morikawa is six shots off the pace after posting a second-round 66.

Justin Thomas (66) registered his 51st bogey-free round of his career. The 14-time PGA Tour champion, who is two under, recorded his 102nd round of 66 or better since 2012 – marking the fourth best on Tour.

Meanwhile, US PGA Championship winner Mickelson missed the cut, despite a heroic 69.

Mickelson, who made history at last week's PGA Championship after the 50-year-old became the oldest major winner in golf history, ended the event two over – just a shot outside the cut line.

Joaquin Niemann is part of a three-way tie for the lead after the opening round of the Sony Open in Hawaii.

The Chilean carded an eight-under 62 at the Waialae Country Club on Thursday to lead alongside Peter Malnati and Jason Kokrak.

Coming off a play-off loss to Harris English at the Tournament of Champions, Niemann's fine start to 2021 continued.

The 22-year-old made seven birdies, a bogey and an eagle, the latter coming with a chip in at the 18th.

Kokrak produced a bogey-free opening round, while Malnati mixed nine birdies with one bogey.

At the 17th, Kokrak almost produced a hole-in-one, only to see his shot lip out as he was forced to settle for a birdie.

Vaughn Taylor, Jim Herman, Aaron Baddeley, Patton Kizzire, Daniel Berger and Kim Si-woo are two shots adrift of the leaders.

The champion in 2018, Kizzire made a 45-foot eagle putt from off the green at the ninth, while Baddeley – runner-up in 2003 – is also in contention.

A group of 13 players are at five under, including last year's runner-up Brendan Steele, 2014 runner-up Chris Kirk and 2012 U.S. Open champion Webb Simpson.

Defending champion Cameron Smith opened with a three-under 67 to be in a tie for 40th.