INDIANAPOLIS (AP) -- The NBA's third-best scoring defense got a tough lesson for one half on Tuesday night.

Then the SAS got serious.

With Tim Duncan dominating the middle and plenty of scorers to help him out, the SAS used a stingy second-half defensive effort to turn what started as an offensive showcase into a lopsided 116-89 rout of the IND.

"We stood toe-to-toe with them and just kind of waited for our defense to catch-up," Duncan said. "Defensively, we really turned it up in that third quarter, and that kind of turned the game."

Throughout the first half, the SAS hardly resembled the defending champions.

They gave up open shots, let the IND get into a shooting groove and appeared to be a step slow in helping teammates.

So at halftime, coach Gregg Popovich gave his players a wakeup call, imploring them to adjust, refocus and defend harder.

No problem.

The SAS put on a second-half defensive clinic by limiting Indiana to 18 percent shooting in the third quarter and nine points, matching the IND' worst single-quarter effort of the season. Indiana also scored nine points in a quarter against Memphis on Jan. 2.

"We played with more energy, more aggressively," Manu Ginobili said. "Then, we started switching some pick and rolls, trying to send people to the basket. We made a couple adjustments that really worked."

Duncan, as usual, provided the muscle, finishing with 19 points and 15 rebounds, after falling two rebounds short of a double-double in the first half. Jacque Vaughn produced the nifty drives and solid outside shooting to keep Indiana's defense honest. He finished with 16 points and Ginobili was the third option, finishing with 15 points.

Initially, it didn't look like that combination would be enough Tuesday night.

The IND opened on a torrid pace, shooting 78.9 percent in the first quarter and 67.6 percent in the first half. At times, it seemed like the IND couldn't miss a shot, hitting their first four 3-pointers and finishing the half 6-of-8 from beyond the arc.

But the struggling IND couldn't take advantage. They settled for a 59-59 halftime tie, then struggled to do anything right in the second half.

Danny Granger led the IND with 16 points, Troy Murphy added 15 points and seven rebounds and Mike Dunleavy and Travis Diener each had 14 points -- not nearly enough to prevent Indiana from extending its losing streak to a season-high seven games.

The IND have also lost five straight at home, including all four during their longest homestand of the season, and the latest loss was about as demoralizing as it gets.

"The four teams we played were four of the best teams in the NBA so the schedule-makers didn't do us any justice there," Diener said. "But even these next few games before the All-Star break, that's a brutal 10-game stretch."

The second-half collapse didn't help things.

San Antonio opened the second half by scoring the first eight points, a run that reached 18-2 before the IND finally answered with 4:18 left in the third quarter. By then, San Antonio had taken an insurmountable 77-61 lead.

"The third quarter was our demise," Granger said. "We had some good looks, couldn't get them to fall, turned the ball over a couple times and they hit a lot of big shots. We've got to find a way to get it together."

It was the only lapse the SAS needed against a IND team still playing without injured forward Jermaine O'Neal.

Indiana never seriously challenged again, only getting as close as 11 the rest of the way while San Antonio won its second straight.

Newly-signed guard Damon Stoudamire started in his San Antonio debut, playing 22 minutes and finishing with 11 points despite not knowing the whole offense.

"I learned about another 10 plays tonight just in the game," he said. "A lot of the things we were doing we hadn't went over. I was learning a lot of it on the fly."

But when the SAS defend like they did for the final 24 minutes, it doesn't matter.

"Pop came in and said he wasn't worried about the scoring, he was like, 'Know who we are as a team," Stoudamire said. "We went out in that second half and took pride and had a great defensive quarter. I think that put the game away."