Defending champion Jack Nicklaus fired five consecutive birdies, three from off the green, on the final five holes yesterday to win the $250,000 Jackie Gleason Inverrary Classic by one stroke over Grier Jones.

Nicklaus, who started the day two shots behind leader Hale Irwin, shot a seven-under-par 65 over the par-72, 7,127-yard Inverrary Country Club Course to win the $50,000 first prize.

Nicklaus finished with a 12-under-par 276. Jones wound up with 277 and Irwin had a 278.

On the 18th hole, Jones was short on a birdie try of 15 feet, then Nicklaus sank his putt of about three feet.

Nicklaus, who won his 64th tour victory, second only to Sam Snead's 84 and his third here, began his charge on the 436-yard, par-four, No. 14 when he sank a birdie chip of 80 feet.

On the 532-yard, par-five No. 15, he hit his second shot into the woods and then chipped up to the fringe. He chipped in for a birdie. On the 199-yard, par-three No. 16, he was again on the fringe and chipped in for a birdie. He hit the green with his second shot on the 400-yard, par-four No. 17 and ran a putt of 25 feet into the hole.

Throughout Nicklaus' hot streak, Jones never crumbled although he played in the same threesome with nicklaus and Irwin, who also challenged most of the day and finished with a three-under-par 69. Irwin wound up the tournament at 10 under par, enough for third place.

Jones, the first-day leader who was in second place after the third round, fired five birdies for a five-under-par 67 but missed birdie putts of 20 feet on No. 16, five feet on No. 17 and the 15-footer on 18.

Nicklaus played consistent golf on the front nine, but managed only a one-under-par 35 when several putts failed to go in. He made the turn two

Nicklaus missed a six-footer on the shots behind Irwin and Jones, who were tied for the lead. fourth for a bogey 5 and had to settle for a par on the next hole when he missed a three-foot birdie putt.

But he managed to stay in range with two birdies. On the first hole he sank a six-footer for a 3 and on the par-four ninth holed a 20-footer for another birdie.

Jones started his round in spectacular fashion, hitting his second shot into the right trap, but holing his sand shot from 80 feet for his birdie. He added his other front nine birdie by holing a 12-foot putt on the par-four fourth.

Irwin fired a 34 on the front nine, but dropped out of the lead with a bogey 5 on the 10th. He rallied with three more birdies in the next five holes, but it ended for him when he hit his tee shot behind a trap and his chip rolled 20 feet beyond the cup for a bogey on the 16th.