Phil Chener wasn't expecting to play much tonight in his first NBA game in 13 months. He was in for the shock of his life.

Chenier wound up playing 21 minutes, including 20 straight from late in the third period until early in the second overtime of tonight's sparkling 138-136 victory over San Diego.

"I wasn't really tired," Chenier said, "just really happy I could contribute. This is quite a team. They keep coming and coming and then win these things. There is a feeling here I didn't see before I got hurt last year. Things have changed."

Chenier's last previous game was Jan. 8, 1978, before he underwent back surgery that he thought might end his career.

Instead, he found himself last night playing an integral part in a Bullet victory 48 hours after being sent to San Diego by General Manager Bob Ferry.

Chenier replaced Mitch Kupchak, who has a sore Achilles' tendon and is on the injured reserve list. Kupchak must miss five games, but he can return if healthy after next Tuesday.

Chenier's presence here actually was required because guard Kevin Grevey also was forced to stay in Washington because of a sore hamstring. Grevey will not play on this road trip, but he could suit up when the Bullets return to play Houston.

Chenier played only briefly in the first half, and his only shot was blocked. With the club down by 20 late in the third period, Bullet Coach Dick Motta turned to Chenier and three other subs. "I didn't want to see my starters in there any more," Motta said. The reserves responded by rallying for the triumph.

Chenier made a 15-foot jumper with 18 seconds left in the third quarter to get rolling.

"I was loose by then," he said, "and the shot really felt good." He finished with six points, but, more importantly, did a decent defensive job on Lloyd Free much of the late part of the game.

Free had 45 points, but where he had been firing over smaller Bullet guards, Chenier made him work for many of his shots.

"It wasn't easy guarding him," Chenier said, "but there isn't much choice. You either get him or Randy Smith."

Chenier's field goal with 14 seconds left in the first overtime gave the Bullets a 125-123 lead before Free forced the second extra period with a jumper. Chenier finally tired after three straight Free baskets and was replaced by Charles Johnson, who popped up the winning points.

Chenier's trip to the West Coast Monday took 12 hours, thanks to bad weather and missed connections. His luggage was in transit even longer.

"You usually would get upset about those things," he said, "but after this game, I couldn't get mad about anything."