NBA PLAYOFFS : Hey, Who’s on Ropes, Anyway? : Pro basketball: Lakers still trail and don’t have home-court edge, but Van Exel’s shots change momentum heading into Game 6.

Maybe because the moment would serve as its own exclamation point, Nick Van Exel did not break into his trademark shadow-boxing routine Tuesday night after landing that devastating haymaker in San Antonio. But, no question, the Spurs were staggered.

Near midnight, in a cubbyhole office just outside the home locker room in the Alamodome, several Spurs crowded around two small TVs.

The one on top had the Phoenix-Houston game going live. That was to have been their immediate future, since the winner of that series would, according to the Spurs’ plan, open the Western Conference finals in San Antonio, perhaps as soon as Saturday.

The picture below was showing their immediate past.

They watched the final 12 or 13 seconds of the overtime game against the Lakers, again and again: Elden Campbell’s near miss on the up-and-under move . . . Vlade Divac controlling the long rebound and shoveling the ball out to Van Exel . . . Van Exel making the three-point runner with half a second left.

They rewound, then reviewed.

“Everyone is disappointed,” David Robinson said, summing up the revolting development. “Now we have to go to L.A. and get the work done. We’ve made it tougher on ourselves.”

Tonight at the Forum, it’s Round 6. The Spurs still have the series lead, 3-2, but the Lakers, still facing elimination, have the momentum. Ding, ding.

“It’s a good test,” San Antonio guard Avery Johnson said. “You can either go up or down. We know what our goals are. We know where our sights are. Nobody said it was going to be easy.”

Nobody said it was going to be like this, though, either. What might be most distressing to the Spurs was their lack of killer instinct against an opponent struggling mightily merely to get a basket. The Lakers went 10 minutes 33 seconds of the fourth quarter without a field goal and still managed to get into overtime.

That kind of missed opportunity is supposed to go with young clubs, like the Lakers. It’s how they lost Game 2 of this series and what contributed greatly to the defeat in Game 4, when San Antonio went 9:19 of the fourth quarter without anything more than a free throw and still won by nine.

But it was the Spurs, loaded with veterans and confidence to the point of boasting that Tuesday would be the end of the Lakers, doing the wondering.

Ultimately, San Antonio’s night was ruined from within as much as by Van Exel. Coach Bob Hill said his team lacked “an aggressive posture” and called it the Spurs’ worst performance of the playoffs.

“We are still in control at 3-2,” he added. “We have to win one more to get it over with and rest. To achieve something significant, it very rarely comes easy.”

On the other side, the Lakers, the youngest team in the playoffs and unproven at this level, seem to be finding a way.

In Game 5, it was Van Exel with the game on the line. Twice, he spurned timeouts that would have allowed the Spurs to set their defense, taking the moment upon himself.

Twice he succeeded. He sank a three-point shot to force overtime, then sank another to force Game 6.

“We’re young,” Cedric Ceballos said. “But we definitely have some courage.”

Laker Notes

The Lakers are trying to become only the fifth team in NBA history to win a series after trailing 3-1, and the first since Boston in the 1981 Eastern Conference finals. The 1970 Lakers also did it, against Phoenix. . . . Laker players said they had not seen any of the comments from some Spurs, namely Sean Elliott and Willie Anderson, that the series would end Tuesday in San Antonio. But Coach Del Harris took note of them after the Game 5 victory. “Some of their players talked an awful lot in the papers,” Harris said. “That’s uncalled-for.”

Nick Van Exel played all 53 minutes Tuesday and has now played 417 of a possible 442 minutes in the nine playoff games. He has committed 21 turnovers in that time but has averaged 20.8 points, 6.9 assists and 2.22 steals.

Which two teams were among those fighting to trade up early in the second round of the 1993 draft when it became apparent that Van Exel would slip? Seattle and San Antonio, and both have paid dearly in the playoffs for it. The Lakers, of course, got Van Exel at No. 37. The Spurs, eager to get a point guard after having let Rod Strickland and Avery Johnson go as free agents, ended up with Chris Whitney at No. 47. They reacquired Johnson before this season.