The leaderboard was bunched up in Doha due to unusually calm and warm conditions.
With Kaymer and Garcia at 9 under were overnight leader Ricardo Santos and Marcus Fraser.
Former U.S. Open champion Michael Campbell was among five players a shot back. Another five were a further shot back at 7 under.
Three shots behind after the first round, the former top-ranked Kaymer stormed into the lead thanks to his short game. He holed a chip from the fringe on 13 and made several long putts including for birdie on the ninth. Kaymer (67) had a bogey-free round that featured five birdies.