Thunder Take Lead as Their Young Stars Best the Spurs’ Veteran Ones

SAN ANTONIO — They finished the regular season with the best record in the N.B.A. They won 20 straight games, including the first 10 of the playoffs. They dazzled opponents with selflessness and precision. Just days ago, with a 2-0 lead in the Western Conference finals, a return to the N.B.A. finals appeared on the horizon for Tim Duncan and the

But then, in Oklahoma City, came the Thunder, followed by a dark cloud that appeared over San Antonio late Monday night. Suddenly in deep jeopardy is the reign of Duncan, a four-time champion, and the Spurs as a perennial championship contender.

The youth and athleticism of the Thunder were too much for San Antonio’s beloved Spurs in Game 5, with Oklahoma City winning, 108-103, behind their young stars, Kevin Durant and Russell Westbrook, at the AT&T Center.

Durant — referred to by Spurs Coach Gregg Popovich as “arguably the best player on the planet” — erupted in the second half to score 22 of his 27 points, while Westbrook added 23 points and 12 assists. James Harden, the N.B.A’s sixth man of the year, scored the decisive basket during a late Spurs run, a southpaw 3-pointer from the right wing.

“That’s what great players do, stay in the game plan,” Coach Scott Brooks said of Durant’s second half. “Kevin did a good job of staying in. Great scorers, there are going to be halves of games when they don’t get shots, or make shots. But Kevin works like he has no talent.”

Manu Ginobili led the Spurs, who had won 16 in a row at home, with 34 points but missed a rushed 3-pointer with a chance to tie the game in the final seconds. Going home for Game 6 Wednesday night, the Thunder will have a chance to become the 15th team in N.B.A. history to win a best-of-seven playoff series after trailing, 2-0.

“It’s not like we’re playing the Sisters of the Poor,” Popovich said. “I don’t care who you are, you can’t turn the ball over 21 times for 28 points.” Near-desperate times call for sensible measures. With the Spurs needing to protect home court and avoid heading back to Oklahoma City to face an elimination game, Popovich decided that he no longer had the luxury of starting the 24-year-old Danny Green at the shooting guard position and deploying Ginobili as his shot of adrenaline off the bench.

But before Ginobili could do anything of note, the Spurs got a presumed lift when Serge Ibaka — whose 26 points on 11-for-11 shooting raised eyebrows and the roof in Oklahoma City in Game 4 — went to the bench with two fouls in 44 seconds.

Be it Ginobili’s energy or the electricity of the home crowd, the Spurs jumped out to an early lead, courtesy of perimeter playmaking by Ginobili. Twice he forced the Thunder to have a help defender cut off his lane to the basket, leaving shooters — Boris Diaw for a 3 and Duncan — open for jumpers. Between those possessions, Ginobili went back door and took Duncan’s pass in stride for a layup.

Meanwhile, the Thunder’s only field goal of the first six minutes came from Nick Collison on a dunk.

When Ginobili took a seat with 5 minutes 13 seconds left in the quarter, the Spurs led, 15-10. Duncan followed him with two fouls 45 seconds later. With that, the young legs of the Thunder — and a couple of older ones belonging to Derek Fisher — were suddenly alive and in transition.

Westbrook scored on the break off a Green turnover. Collison got another uncontested layup off a Westbrook penetration. The quarter ended with the Thunder ahead by 26-21 and it got worse for the Spurs.

For all the talk about Tony Parker having been a league most valuable player candidate and the Spurs’ M.V.P., Ginobili was all that kept his team from being blown out in the second quarter. His masterpiece of a half — 14 points, 5 rebounds, 5 assists — was Popovich’s only answer to the Thunder’s superior athleticism.

Depth was supposed to be San Antonio’s strength, but nine Oklahoma City players scored in the half — with Westbrook and Durant combining for 11 assists. The Thunder’s bench outscored the Spurs by 25-13, including an 8-point explosion from Daequan Cook. His consecutive 3-pointers from the right corner, set up by Westbrook’s penetration, gave the Thunder a 40-33 lead.

Ginobili answered with one of his own, but the Thunder ran off 10 straight — after Ginobili happened to take a rest — to lead, 50-36. By half’s end, it was 52-44, and the worst realization for the Spurs had to be that the Thunder were in charge with only 5 points from Durant on 1-of-6 shooting.

The Spurs would rally in the third quarter. Ginobili was hot. But Durant — furthering Popovich’s argument — once again started looking like the best player on the planet and the younger, swifter Thunder followed him to within one home victory of this rising team’s first league finals.