Dustin Johnson will take a two-shot lead over Rory McIlroy into the third round of the WGC Mexico Championship.
McIlroy, who has won just one PGA Tour title since 2016, topped the leaderboard after an opening-round 63 but could only follow that up with a 70.
The Northern Irishman made a storming start to his second round, birdieing three of the first four holes, but was back to level for the day after a double bogey at the ninth and only managed one birdie on the back nine.
Johnson was the man to take advantage with a round of 67, posting four birdies and not dropping a shot as he moved to 11 under par.
McIlroy was joined on nine under by Matt Kuchar, who is letting his golf do the talking after last week's caddie controversy and birdied the first four holes in a round of 67.
Sergio Garcia and Tommy Fleetwood are a further two shots back on seven under, two ahead of Tiger Woods, who is among a group of players on five under.
The former world number one hit arguably the shot of the day on the 18th when he played out of a fairway bunker to a matter of feet and, however, despite not holing the birdie putt, he still signed for an impressive 66.
Shane Lowry, meanwhile, fell down the leaderboard after a poor second round.
The Offalyman was just inside the top 20 after an opening round of 70, however, things started to go awry at the fifth hole when he dropped a shot to go one over and, by the turn he had two more bogeys and a birdie on his card.
Worse was to come, however, on the back nine after he dragged himself back to two over while standing on the 15th tee.
A long drive into the fairway looked to set him up well, however, by the time he had picked his ball from the hole, the double-bogey meant that his chances of getting close to par were gone for the day.
A further dropped shot on the next hole left him five-over par for his round and the tournament.
Going in the opposite direction was Phil Mickelson, who might be just three shots ahead of Lowry but will feel far more positive going in the weekend. The defending champion endured a nightmare 79 to open but recovered with a 65 - the joint best round of the day.
Elsewhere, Roberto Diaz, DJ Trahan and Nate Lashley share a three-way tie for the lead after the second round of the Puerto Rico Open.
American Trahan shot a five under par round to propel himself 11 places up the leaderboard while his countryman Lashley and Mexican Diaz, who holed four birdies and did not drop a shot, both went round in four under to join Trahan on eight under par.
Canadian Roger Sloan, who shot an eagle on the 17th hole, joins two more Americans in Martin Trainer and Ben Crane a shot back on seven under par.
Overnight leader Andres Romero has slipped down the leaderboard after a round of 73 left the Argentinian on five under par for the tournament, level with South Africa's Charl Schwartzel after his round of four under par on Friday.