Former world number one David Duval shot a six-under-par 64 to lead the Dunlop Phoenix tournament in Japan.
The American, whose career went into an almost terminal decline after winning the 2001 Open at Royal Lytham & St Anne's, leads by one from defending champion and current world number one Tiger Woods.
Duval has struggled with back problems which caused him to alter his swing and, as a result, his game fell to pieces and in 2004 he took a seven-month break from the circuit.
However, he has gradually been easing his way back and, although he made only one cut on the PGA Tour this season, his return to the Phoenix Country Club in Miyazaki where he won in 2001 sparked a remarkable recovery.
Starting on the back nine he birdied the par-three 11th and the par-four 13th before picking up further shots at the short 17th and par-five 18th to turn in 31 having found his form on the greens.
That was the start of a run of five birdies in six holes - including a chip in at the par-four first - and although he carded back-to-back bogeys at the fifth and sixth Duval finished with his eighth birdie of the day to come home in 33, with a remarkable 24 putts for his round.
By comparison Woods, the best in the world on the greens, took 29 putts in his round of 65 which included six birdies and one bogey.
Duval said: "I played well. I've been playing well for about a month now but just haven't been scoring well. I'm well aware of how I've played over the past few years but I've worked hard and it's good to start a tournament not behind the eight-ball."
Woods, having finished runner-up in his last two events, was satisfied with his round.
"I hit the ball well today and it's exciting to strike the ball that well and consistently. I hit the ball better today than I did for the past two weeks," he said.
On Duval he said: "It's been tough to watch. David is a friend of mine, we played in two World Cups together and he has really struggled but it looks like he's showing signs of getting his game back together."
Scotland's Colin Montgomerie, who won a record-breaking eighth Order of Merit title this year, is seven shots off the lead on one-over after just two birdies and three bogeys.
That is one better than US Open champion Michael Campbell, who carded a 72.
Dubliner Peter Lawrie is ten shots off the pace after returning on four-over-par 74.
