NAPLES, Fla. John Jacobs woke up just in time at the Senior MasterCard Championship.

He started today's second round at the Hualalai Resort Golf Club on the island of Hawaii with the lead and was coasting along with a comfortable five-stroke advantage over Raymond Floyd after 12 holes.

All of a sudden, back-to-back bogeys at the par-4 15th and 16th holes threatened to make it a tight race for the $186,000 first prize.

"I got off to a good start, but I kind of got tired out there," said Jacobs, who gained eligibility to the winners-only tournament by taking last year's Nationwide Championship. "I mentally fell asleep on a couple of holes.

"I hated to three-putt those two holes, but they woke me up. At the end, I just wanted to par out and regroup for tomorrow.

"I was very happy to tie-toe out of there."

Jacobs finished the round with a 3-under-par 69 for a 36-hole total of 11-under 133. Until he faltered, he had been on pace to challenge the 36-hole records for score (13-under) and margin of lead (5).

Floyd started the day three strokes behind Jacobs and had picked up two midway through the front nine to move within a shot. But it became a two-stroke swing on the 425-yard ninth hole when he bogeyed and Jacobs birdied.

Floyd shot a 69 to reach the 36-hole mark at 136.

"I got off to a wonderful start and had it to 9-under (one behind Jacobs), but then it was a different game from there on in," he said. "Johnny's playing very very well. If he continues, he's going to be very difficult to catch.

"If he had a five-shot lead, he'd be almost out of reach. Three is difficult, but I'm in touch. He'll be a tough cookie tomorrow."

Gary Player and Dana Quigley shot 68s to share third place with Bob Dickson at 138. Dave Stockton, Jim Colbert, J.C. Snead and Isao Aoki were at 139, with George Archer and Bud Allin at four-under.

Two of the favourites, Hale Irwin and Gil Morgan, who won 13 of the Senior Tour's 38 official money events last year, faltered after being in contention for 18 holes.

Irwin, who had an opening 68, fell to a 75. Morgan shot a 73 to go with a 69 on Friday.