BANGOR – William Link IV of Acton, Mass., promised that he would return to defend his title in the $50,000 Greater Bangor Open Golf Tournament this year and he has.

With a vengeance.

Link fired a 5-under-par 64 at Bangor Municipal Golf Course Thursday morning and trails leader Rick Karbowski of Worcester, Mass., by a stroke entering today’s second round. The two par 5s on the back nine are converted to par 4s, making the course a par 69 for this tournament.

Karbowski’s round included a sizzling 5-under-par 29 on the back nine.

Tied for third at 65 are Matt Donovan of Pittsfield, Mass., Billy Downes of Enfield, Conn., and Ryan Ouellette of West Palm Beach, Fla.

Another stroke back are Todd Westfall of Clendenin, W.Va., and Dennis Rasku of Deerfield Beach, Fla.

Paul Dickinson of Apopka, Fla., the 2002 GBO champ, heads a group of seven at 67.

Corey Poulin of Milford is the low amateur at 70, a stroke up on Ross McGee of Fairfield and two strokes ahead of Jesse Speirs of Bangor.

“I put it on my schedule once they put out the dates,” said Link of the GBO, which has major co-sponsors in Golf Country and Town and Country Realtors. “The only thing that would have kept me away is if I had Monday qualified for the PGA Tour event [the U.S. Bank Championship in Milwaukee].”

Link likes the atmosphere and other aspects of the tournament that make it enjoyable to return.

“It’s the little incentives – the pro-am, the driving contest, the lunch after the pro-am, the awards ceremony. It makes you feel like you’re in a real tournament,” said Link.

He does know he’s in a real tournament after looking at the list of players.

“He’s tough,” said Link of Karbowski, the reigning New England Open champion. “Not many mistakes, and not many flaws, either.

“Matt Donovan, he’s coming off the Canadian Tour. And Downes was runner-up last year [and 2000 GBO winner].”

Links marveled at the makeup of his threesome, which included Dickinson and Sean O’Hair of Aston, Pa., who tied with Downes as runner-up last year. O’Hair also shot 67.

“Our group was 9 under. Either it was intentional or one very smart computer,” said Link.

Link qualified for the B.C. Open in Endicott, N.Y., last week. He missed the cut but felt he got a boost just from making the field.

“My confidence is up,” said Link. “I know I can go pretty low.”

And he has been recently.

“Twelve of my last 13 competitive rounds, including the PGA Tour ones, have been par or better,” he said.

Link went under par quickly Thursday as he birdied the second hole, but he immediately three-putted the par-3 third.

Back-to-back birdies on Nos. 4 and 5 put him under par for good. He parred the next four holes, including the par-3 sixth, which proved exceedingly tricky to putt for most of the field, to make the turn at 2-under 35.

He opened the back nine with six straight pars.

“I have a new driver that Taylor-Made built for me, and I’ve got it going well,” he said. “I was never in danger of making any bogeys.”

Link then finished with a birdie flurry by sinking a 12-foot putt on 16, a 20-footer on 17, and a 15-footer on 18.

“Making a birdie there is like stealing,” he said.

Link worked with a new coach over the winter with limited success, saw his longtime coach when he returned to New England, then was turned over to a third coach.

He didn’t like seeing so many different coaches, but he keeps working at the changes.

“I’m getting better, and that’s what you’re looking for,” he said.

Karbowski started on No. 10 and birdied the first four holes. He also birdied 17 for his 29.

He added birdies on Nos. 1 and 4 before suffering his only bogey on No. 8.

Donovan started on No. 1 and made four birdies for 31, but he played the back even par.

Downes started on No. 10 and nearly equaled Karbowski as he shot a 30. He matched par on the front.

Ouellette, the 2002 runner-up, played both sides under par – 1 under on the back and 3-under on the front.

After today’s round, the field will be cut to the low 50 and ties among the pros and the low 15 and ties for the amateurs for Saturday’s 18-hole finale.