DALLAS -- The young Oklahoma City Thunder keep getting better. They just are not ready to take that next step yet.
Despite leading on the road for much of Game 5 of the Western Conference finals, they couldn't extend their season after giving Dallas Mavericks star Dirk Nowitzki a second chance.
Nowitzki hit the go-ahead three-pointer with 1:14 left, after Russell Westbrook couldn't handle the rebound on the first missed 3, and the Mavericks went on to a 100-96 victory Wednesday night to advance to the NBA finals.
"It's kind of shocking that our season is over with," Kevin Durant said. "But we fought hard all season. I tried to keep it positive and tell the guys, 'Hey, we had a great year.' Collectively, we've got to keep working."
Until Nowitzki's second-chance three-pointer, the Thunder had been behind for only a minute of the second half and appeared poised to win in Dallas for the second time in the series.
"I just think we played hard and just couldn't come up with the win," said Westbrook, who scored 31 points.
Instead of going home for another game, the team filled with 20-something stars will go home thinking about what could have been.
The Thunder are sure to remember the disappointment of how this series ended. They blew a 15-point lead in the last 5 minutes of Game 4 at home, then couldn't hold on with a late lead when facing elimination.
But at some point they might look back at the series against the Mavericks, a veteran-filled team focused on another championship chance, as a big learning experience.
"We want to win a championship. We respect the process that it takes to win one, and our guys do the same thing, they respect the heck out of the game," coach Scott Brooks said. "You can't skip steps. I don't know how soon we were going to get there, but I can tell you this, those guys are not going to hope to get there, they are going to work to get there."
After taking the Los Angeles Lakers to a Game 6 in the first round of last season's playoffs before a one-point loss ended their season, the Thunder won two rounds this year -- knocking Denver out in five games and needing seven games to get past Memphis.
"It's a different feeling (this year). All of us expected to go far," Durant said. "We had high expectations for ourselves coming into this year. ... After a good first round, hard-fought second round, we put ourselves in good position to fight for a finals appearance and thought we had a good chance."
Oklahoma City did better against Dallas this month than the two-time defending champion Lakers. Los Angeles was swept in its second-round series by the Mavericks, including a 122-86 loss in the same building in the ending game of that series 2 1/2 weeks ago.
"I just know that we played together as a team throughout the whole series, and just couldn't come up with the wins," Westbrook said. "We're not just worried about Dallas. We've got a whole next year to come up to worry about other teams. We're going to come in and just get better."
Westbrook and Durant are 22-year-old standouts for the Thunder, whose oldest starter for Game 5 was 27-year-old guard Thabo Sefolosha.
The Mavericks' youngest starter was 28-year-old Tyson Chandler, in his 10th NBA season.
"Next year when they're 23, they're still going to be young. We're not going to use it as an excuse," Brooks said. "I know our guys, they improve all the time. They're real committed to each other. I've never been on a team other than my high school team that we had a closer group of guys and they are all the same age and they're fighting to get better."
Durant and James Harden scored 23 points apiece. Durant, who after Game 4 apologized to Thunder fans for letting them down, was 8-of-20 shooting with a long drought in Game 5.
Oklahoma City had an 88-83 lead when Brooks called timeout with six minutes left. After Nick Collison drove for a dunk, the lead was seven points.
Durant, who missed his only shot in the second quarter and missed his first five in the second half, scored on a driving one-handed fadeaway shot with 4 1/2 minutes left to make it 92-86. The Thunder couldn't hold on from there.
"It was a difficult loss for us. We played so well in that game but didn't make enough plays down the stretch," Collison said. "We learned that we're talented enough to play for a championship. But we have to play basketball better. We need to learn how to win games better, and that's difficult."