The two-time major winner from Germany set up another chance for a fourth victory at his regular year-opening tournament, shooting a second straight 6-under 66 Friday to take a one-stroke lead after the second round.
''My favorite golf course,'' Kaymer said after tapping in a birdie on the par-5 18th to nudge ahead of Rafa Cabrera Bello with a 12-under 132 total.
Kaymer has averaged 68.73 in 38 rounds over the 7,583-yard National Course, a long track that suits his eye and his game. He feels extremely confident on the greens – he already has 14 birdies and an eagle this week – and the course's many doglegs is perfect for a player who fades the ball off the tee.
''He's a dangerous player around here,'' said Henrik Stenson, who gave up his first-round lead to his Ryder Cup teammate. ''I think it sets up beautifully for him. He's shown that in the past with three wins here.''
Those victories came in 2008, '10 and '11. The 53rd-ranked Kaymer should have had another in 2015, only to throw away a 10-shot lead with 13 holes to play and get reeled in by Gary Stal.
Kaymer's round on Friday took off after rolling in a 20-foot eagle putt on No. 8, allowing him to rebound from a bogey on No. 6. He birdied six holes on the back nine as the wind died down, having been quite strong in the early afternoon.
Sunny and still conditions greeted Cabrera Bello in the morning and the Spaniard responded with 66 of his own, completed by three straight birdies.
Cabrera Bello has been a regular top-10 finisher on the European Tour in recent years - he had six of them in the 2016 season alone – and his consistency earned him a debut on the European team at the Ryder Cup last year. But his last win came at the Dubai Desert Classic in February 2012.
''A couple of times I felt that maybe I made a few mistakes that I have learned from them,'' said Cabrera Bello, who had seven birdies and one bogey. ''Other times, I just felt that the other guys have outplayed me.
''I know I finished second or third many times but not all of them felt like losses. They felt like good comebacks to finish second or third. I feel like I'm close, but we will know soon.''
There were mixed fortunes for the marquee group of current major champions Danny Willett, Dustin Johnson and Stenson. Willett, the Masters champion, missed the cut after adding a 76 to a 74 and finished 121st in the 126-man field. He had a 9 at the par-5 10th after driving into the desert, hitting the ball out of bounds, then into a bunker before three-putting.
''Christmas golf-course rust,'' Willett said.
Johnson, the U.S. Open champion, shot a bogey-free 68 to move to 4 under overall, alongside defending champion Rickie Fowler (68). Surprisingly, the big-hitting Johnson hasn't picked up a shot in eight tries at a par 5.
Stenson, The Open champion, is best placed of the big names. His 71 lacked the fireworks of his first round, when he shot 64, but the Swede said he felt he was hitting the ball better.