South African Tim Clark, inspired by two eagles, opened a one-stroke lead with a sparkling nine-under-par 62 in the Deutsche Bank Championship second round on Saturday.

Five off the pace at the start of another day of low-scoring at the TPC Boston, he briefly raised hopes of a magical 59 before bogeying the last two holes for a 14-under total of 128.

"It just was strange," Clark told reporters after equalling his lowest score on the PGA Tour. "I felt good all day and just kept making birdie after birdie after birdie.

"And then on the front nine, my back nine, a couple eagles really boosted the round. For a while there, there was certainly a chance of 59."

That left him one ahead of first-round leader Mike Weir of Canada (68), with American Ben Curtis (65) and 2004 champion Vijay Singh (66) of Fiji a further stroke back.

The heavyweight trio of American Jim Furyk (65), Spaniard Sergio Garcia (64) and South African Ernie Els (65) were among a group bunched at 11 under.

Clark, yet to win on the PGA Tour, raced to the turn in five-under 30 after teeing off at the par-four 10th in damp, overcast conditions.

He picked up another shot at the first before hitting a three-iron to eight feet at the par-five second to set up his first eagle.

The 32-year-old also eagled the 290-yard, par-four fourth when he rolled in a 22-foot putt after his drive ended up narrowly short of the green.

Another birdie followed at the seventh when he struck a wedge approach to two feet and he needed to pick up one more shot to become the fourth player to fire a 59 on the PGA Tour.

However, Clark bogeyed the tricky par-three eighth after missing the green to the right and also dropped a shot at the ninth when his par putt lipped out from nine feet.

"Once my putt on eight missed, that was the end of the dream," he said. "That hole was always going to be tough but I felt I hit a good (par) putt there.

"But I'm certainly not disappointed. I've still got 36 more holes to play and a lot of golf left. Disappointed about the 59 but I need to keep going if I'm going to win this tournament because the scores I think are only going to stay low."

American Al Geiberger was the first player to break 60 on the PGA Tour, shooting a 13-under 59 in the second round of the 1977 Memphis Classic.

Chip Beck did likewise in the third round of the 1991 Las Vegas Invitational before David Duval repeated the feat in the fifth and final round of the 1999 Bob Hope Classic.

Weir, who took control of the second event in the FedExCup playoff series with a sizzling 61 in the first round, was delighted to recover from two bogeys in his first four holes.

"It wasn't a great start but there's lots of golf to be played and I just kept telling myself that," the 2003 U.S. Masters champion said. "I knew I was playing fine."

The cut fell at three-under 139 with title-holder Phil Mickelson scraping through right on the number after shooting a 70.

British Open champion Padraig Harrington of Ireland, twice U.S. Open winner Retief Goosen and European Ryder Cup hopefuls Paul Casey and Ian Poulter were among those who missed out.