Henrik Stenson, who has finished second and eighth here the last two years, is alone in second place at minus-5.
Adam Scott, the eighth ranked player in the world, opened with a 4-under-par 68 and shares third with Robert Karlsson. Lee Westwood, Ignacio Garrido and Peter Hedblom are one stroke further back at minus-3.
Kaymer started his round on the 10th tee at Abu Dhabi Golf Club. He got off to a hot start as he eagled the par-5.
After four straight pars, Kaymer tripped to a bogey on the par-3 15th. The German recovered that lost stroke with a birdie on the par-5 18th.
'I had a really good start. I started out with a nice eagle and was 2 under after the first nine holes,' Kaymer stated.
Around the turn, Kaymer moved to 3 under with a birdie on the par-5 second.
Kaymer birdied the fifth and seventh to join Stenson atop the leaderboard at minus-5. However, Kaymer grabbed the lead by himself as he birdied the par-4 ninth, his last.
'It was a really nice round. It was a nice start to the season,' said Kaymer, who last played at the World Cup in late November. 'When you play a lot of tournaments in a row, you don't feel the nerves, but since I haven't played in a few weeks, I felt them on the first tee today.'
Stenson, who teed off in the morning wave, also started on the back nine. He opened with three straight pars and followed with three consecutive birdies to fly up the leaderboard.
The 31-year-old birdied the 18th to make the turn at minus-4, but trouble loomed. Stenson bogeyed the first, but atoned for that error with a birdie on the par-3 fourth.
Stenson, who set the course record of 62 here in 2006, dropped another shot at five, but bounced back to birdie the sixth to get back to 4 under. He closed his round with a birdie on the ninth to end one back.
'It is definitely one of my goals for the future to win this tournament and if it is in the very near future, then no one would be happier than me,' said Stenson, who now lives in nearby Dubai. 'I made a great putt on the last to go to 5 under and I'm delighted with the start.'
A group of 13 players is tied for eighth place at 2-under-par 70. Among those are Gonzalo Fernandez-Castano, Paul Lawrie and Ian Poulter.
There is another large group of players at minus-1 and among that group is Luke Donald, Ricardo Gonzalez and Thongchai Jaidee.