The San Antonio Spurs know a thing or three about fourth-quarter collapses. It has been the story line of their postseason, personified by an epic debacle in Game 5 when they blew a 19-point lead to an undermanned Dallas Mavericks team.

Must've been contagious. Because with a chance to extend the series to seven games Thursday, the Mavs broke down like an old car in the fourth quarter. In a Western Conference finals in which the home court was a disadvantage --- the home team won just one game --- the Spurs advanced to their first NBA Finals since 1999 by --- what else? ---defeating the Mavericks on the road 90-78.

Spurs guard Stephen Jackson scored a career-playoff-high 24 points and kept playing while most of his teammates sleepwalked through the first three quarters. His energy spread to reserve Steve Kerr, who came off the bench cold but quickly heated up during a stunning 23-0 fourth-quarter run.

Kerr, 37, was playing because Spurs point guard Tony Parker was fighting food poisoning and backup Speedy Claxton was mostly ineffective. Dallas built its lead to 55-42 in the third period after Claxton threw away passes on two of three possessions, then had his shot blocked on the next.

Spurs coach Gregg Popovich then turned to his third-string point guard, Kerr, a 14-year veteran who won three championship rings with the Chicago Bulls and one with the Spurs in 1999. He sank three of his team's six 3-pointers in the fourth quarter as the Spurs erased a 13-point deficit and outscored the Mavs 34-9 in the period.