In 2005, Tiger Woods overcame a two-shot deficit on Sunday to defeat Phil Mickelson in one of the PGA Tour's best duels.
'I'm going to try and keep stride with Tiger and maybe we can have another shot at it on Sunday like we did last year,' said Mickelson.
Mickelson was joined in second place by former PGA Champion Rich Beem, Mark Wilson, Ryan Palmer and Camilo Villegas at seven-under-par 65.
Another former PGA Champion, David Toms, posted a 6-under-par 66 and is in seventh place along with Dean Wilson, Scott Verplank, Daniel Chopra and Michael Bradley.
Woods wasted little time getting into red figures on Thursday. He birdied three of his first four holes, including a tap-in at the par-three fourth hole.
The reigning Masters and British Open winner parred his next six holes, but birdied 11. At the long, par-5 12th, Woods was able to reach the green with his second, then two-putted for a birdie.
Mickelson was 5 under par playing the course from the 10th tee, then drained a 7-footer for birdie at his 14th, No. 5 at Doral. He collected another at six to get to 7 under par for the championship.
Woods kept pace. He chipped in for birdie from 25 feet away on the fringe at the 15th, which put him into a tie for the lead at minus-7. He tapped in a 3-footer for birdie at No. 16 to move into the lead.
Both players squandered chances on the way into the clubhouse. Mickelson, last year's PGA Championship winner, missed a nine-foot birdie putt at the seventh and a drive into a bunker halted his birdie chances at the par-5 eighth.
The lefthander had close to 30 feet for birdie at the par-three ninth, but the ball stayed above ground. Mickelson still posted his lowest score of the 2006 season.
'It was fun,' said Mickelson. 'I felt like I had pretty good control. I hit some good shots. I seem to roll them in today. I'm optimistic for the next few days.'
Woods narrowly missed a 25-foot birdie putt at 17 and struggled on the closing hole. His drive landed in the rough, then he caught a flier lie that sent the ball through the green. Woods elected to putt and his birdie putt moved four feet right. The No. 1 player in the world converted the par putt for the first-round lead.
'I hit the ball well today and also made a few putts.' said Woods, who won his first two starts on the season at the Buick Invitational and in Dubai. 'It's nice to get on true greens again.'
This event features nine of the top-10 players in the world. Number two Vijay Singh shot a 5-under 67 and is part of a group tied for 12th place. Retief Goosen, third in the rankings, carded a 2-under 70 to get into a tie for 61st, while Ernie Els, the 2002 champion, only managed an even-par 72. He is part of a group in 98th place.