Dirk Nowitzki scored a go-ahead 3-pointer with 1:14 left and Shawn Marion followed with a three-point play as the host Dallas Mavericks booked a spot in the NBA finals with a 100-96 victory over the Oklahoma City Thunder yesterday.

The pivotal plays keyed yet another fourth-quarter comeback, this one helping the Mavericks close out the Western Conference finals in five games.

After clawing back from 15 points down with 5:04 left in Game 4, the Mavericks were down by six with 4:37 left in this one when they rallied again, outscoring the Thunder 14-4 the rest of the way.

Dallas has never won a championship, and neither has any of its players. Nowitzki and Jason Terry were part of the only Mavericks team to make the finals, in 2006. They were up 2-0 and leading late in Game 3, but lost the series to the Miami Heat in six games.

Dallas could get another chance to play the Heat.

LeBron James and Miami lead the Chicago Bulls 3-1 in the Eastern Conference finals. If the Heat win Thursday, the finals will begin Tuesday in Miami. If the Bulls win Thursday, the finals will begin next Thursday in the East winner's city.

"All I can tell everybody is, we ain't done yet," Mavs owner Mark Cuban said during the on-court trophy presentation ceremony. Seconds later, fans began chanting, "Beat the Heat," drowning out coach Rick Carlisle's on-court interview.

Nowitzki and Marion each scored 26 points, and were at their best in the fourth quarter. Nowitzki scored nine in the final period, and Marion had 15. J.J. Barea added 14, Terry scored 12 and Jason Kidd had 10 assists and seven rebounds in a victory that set off the biggest on-court celebration in franchise history.

The only other time the Mavs made the finals, they won in Phoenix. This time, the home folks got to enjoy it, including franchise founder Don Carter, who traded his signature white cowboy hat - the one that used to be featured in the team's logo - for a black hat that read "The Finals 2011" with a Mavs logo and the championship trophy. Fans roared again when the overhead video board showed Nowitzki wearing the hat.

Russell Westbrook scored 31 points and seemed to be on a mission to force the series back to Oklahoma City. But he had two crucial turnovers during the furious finish.

Kevin Durant and James Harden finished with 23 points apiece for the Thunder, who bowed out with only their second three-game losing streak of the season.

Considering their youth and the experience gained in this series, Oklahoma City can expect to close in on many more titles. But that was little consolation yesterday.