The San Antonio Spurs usually do not waste much energy playing defense, but Larry Kenon shut down Julius Erving today and the Spurs held on for a 115-112 victory at the Spectrum.

The Spurs now are only one game away from eliminating the 76ers from the playoffs, leading the best-of-seven Eastern Conference semifinal series, 3-1.

George Gervin scored 32 points, 14 in the fourth quarter, to give the Spurs the big baskets they needed and Kenon held Erving to 15 points and forced the frustrated Doctor into a number of bad shots.

Erving made only six of 17 attempts in the game. He had 11 of his points in the final 6:48, when the 76ers were trying frantically to catch up.

"We're in the driver's seat, but that dosen't mean we can't have an accident," San Antonio Coach Doug Moe said. "I'm thrilled with the win, but I'm not overconfident."

Game five will be played Thursday in San Antonio. If a sixth game is necessary, it will be played at the Spectrum Sunday.

"We won't be back here, no way," said San Antonio guard James Silas.

San Antonio had an 11-point second-quarter lead, but could never put Philadelphia away. It took eight Gervin points in the final 1:29 to seal the victory.

Erving scored on a picturesque reverse layup before Bobby Jones tipped in a missed Erving shot to bring the 76ers to within two points, 106-104, with 1:43 to play.

Gervin then went one-on-one against Maurice Cheeks and forced the 6-foot-1 rookie to foul him. Gervin made two free throws. He then stole the ball from Jones at the other end of the floor and turned it into a fast-break dunk and a 110-104 San Antonio lead with 1:11 left.

Erving followed with a 15-foot jump shot, but on San Antonio's next possession, with the 24-second clock running down, Gervin hit a 22-foot jumper from the deep right corner and a collective groan escaped from the Spectrum crowd of 11.163.

Erving then scored quickly and fouled Silas to stop the clock with 28 seconds left and the Spurs on top, 112-108.

Silas made one of two free throws for a 113-108 San Antonio lead.

The 76ers rushed the ball upcourt and Erving scored on an 18-footer. With the 76ers pressing full court, Silas was called for an offensive foul as he tried to dribble around Jones with 17 seconds remaining.

Erving missed a jump shot, but Jones tipped in the shot to cut San Antonio's lead to 113-112 with 10 seconds left.

Silas kept the ball in the backcourt until two seconds remained and then threw it to Gervin in the front court. Time ran out just as Erving got to Gervin and fouled him.

Gervin made two free throws for the three-point final margin.

"We were in control at the end," Silas said. "I knew just how much time was left and that if we stayed calm, there just wasn't enough time for them to catch us."

Cheeks scored a career-high 33 points for Philadelphia. But with Erving, who had 39 points in Philadelphia's victory Friday, not a factor on offense until the final minutes of today's game, the 76ers often were disorganized and never got into a groove.

Kenon, who scored 23 points and added nine rebounds, six assists and three steals, said he didn't know he was going to guard Erving until just switch. Allan Bristow had started against Erving in the three previous games.

"Most people play a sagging defense on Erving, but I tried to deny him the ball and keep him as far out as possible, " Kenon said.

"Kenon played Doc awfully well," Moe added. "We just tried to double-team him when he went low and when he went one on one. Larry is quick enough to keep him from penetrating and he kept Doc off the boards."

Erving said things look "dim" for the Sixers now.

"I think we got outplayed," Erving said. "They gave us a couple of chances to get back into it, but we didn't capitalize on them.

"Kenon did a good job on me. He denies the ball well and he has great anticipation. His defense was the biggest factor in me missing so many shots."

Philadelphia Coach Billy Cunningham complained about the officiating, calling it "the poorest officiated game I've ever coached in the playoffs. I thought it was pathetic."

Cunningham drew a technical foul for complaining in the second quarter. His team still went to the foul line five more times than San Antonio did.

Looking ahead to Thursday's game, Cunningham said, "I guess you could say we are in trouble."

"I think he's right," Silas said.