SAN ANTONIO (AP) – Robert Horry came to the San Antonio Spurs as a castoff.

Two months before he signed as a free agent with the Spurs in July 2003, Horry endured the worst postseason of his pro career. He missed all but two of his 38 3-point attempts, and his Los Angeles Lakers lost in the second round to the eventual champion Spurs.

The Lakers declined to exercise a $5.3 million option to keep Horry, but the last laugh is his – the Lakers are a lottery team and Horry is once again a playoff hero.

His 3-pointer with 5.8 seconds left in overtime Sunday gave the Spurs a 96-95 victory over the Detroit Pistons in Game 5 of the NBA Finals.

San Antonio holds a 3-2 edge in the best-of-seven series, with Game 6 on Tuesday at the SBC Center.

“It’s the playoffs, man,” Horry said. “If you don’t get excited about the playoffs, you don’t even deserve to be playing basketball. I get excited for the regular season, also, but it’s just added excitement when the playoffs start.”

His excitement has paid off for the teams he’s played for and earned him five title rings. In May 2002 with the Lakers, he hit a 3-pointer to beat Sacramento in a Western Conference final game and even the series at two games apiece. A month earlier, he made a 3-pointer to clinch a first-round series against Portland.

“You don’t play on championship-caliber teams unless you have what he has,” Detroit coach Larry Brown said. “He’s done it with Houston, he’s done it with L.A. and now he’s done it with San Antonio, and he usually does it at the most important time.”

Two years ago, Horry couldn’t buy a basket.

He had the ball on the same spot behind the 3-point line and in the same playoff game-deciding scenario as he found himself Sunday night.

The three-time defending champion Lakers were tied at two games apiece with the Spurs in a second-round series. The Spurs led 96-94 at home with just a few seconds remaining in Game 5. Horry let fly with a 3-point attempt from the left wing that landed inside the rim, rattled around and then skipped out into David Robinson’s waiting hands.

It was Horry’s 15th miss in as many tries from behind the arc in that May 2003 series, won by San Antonio in six games. A few weeks later, Horry was let go by Los Angeles.

“We were immediately interested in him because we felt that he still had good years ahead of him,” San Antonio coach Gregg Popovich said Monday. “When you round out a team, it’s important to find people that come and play at playoff time. That’s always a consideration – How will he do in the playoffs? … Will he take the big shot?”‘

Of course, Big Shot Bob will take the big shot – the bigger the stakes, the better. His 49 3-pointers in NBA Finals games is a record.

Horry’s latest dramatic game-winner was just the finishing touch on a remarkable scoring spurt. All 21 of his points, including five 3-pointers in six attempts, came in the final 17 minutes.

“That was probably the greatest performance I’ve ever been a part of, to just see him there and to see him as calm as he was and willing to do whatever,” teammate Tim Duncan said.

It wasn’t even certain that Horry would have the strength to make the decisive 3-pointer, set up by a perfect bounce pass from a double-teamed Manu Ginobili. A minute earlier, Horry barely reached the rim for a lunging left-handed dunk that left him clutching his left shoulder. He was fouled on the play, and his free throw fell way short.

“I was really worried about him because he does have a problem (with that shoulder) and he keeps reinjuring it,” Popovich said. “But obviously it doesn’t stop him from being aggressive.”

Horry said of the dunk, “When I was going through the air I was like, Please let me get there, please let me get there.”‘

Hundreds of cheering fans were there to thank Horry for his good aim when the Spurs arrived from Detroit in the wee hours Monday, and he thanked them right back.

“If you can’t beat em, join em,” he told the raucous airport crowd, “and I’m so happy to join the Spurs.”