Having flown into the lead on the first day, it was always going to be hard for Mahan to maintain his level of performance.

As the American's second round levelled out, Kaymer steadily chipped away at the lead, eventually reducing the deficit between them to one shot going into the third day.

The world number one stated that he was pleased with his performance in Florida and that he was focussing on one tournament at a time rather than worrying about his ranking.

"I love so much to be in contention every week. That is what golf is all about and that is why I practise so hard - to be in that position as much as possible.

"I'm the number one in the world for at least two weeks. Hopefully if I keep playing the way I do then another week. And then we'll see.

"I don't really worry about the world rankings. I think you only have to worry if you play bad golf."

Also in contention is Francesco Molinari, who managed to sink two birdies on the last two holes to match Kaymer at eight under par.

British players Martin Laird and Rory McIlroy are in with a shout going into the 3rd day. Both of them are sitting at seven under, which puts them in a great position to mount a serious challenge in the remaining rounds.

Tiger Woods had a day to forget, making several mistakes with his driver and posting an underwhelming score of 74 taking him to level par. He shares this position with Lee Westwood.