Dallas Mavericks' Dirk Nowitzki of Germany, Tyson Chandler, and Peja Stojakovic (L-R) celebrate during Game 4 of the NBA Western Conference Final basketball playoff against Oklahoma City Thunder in Oklahoma City, Oklahoma May 23, 2011. REUTERS

Oklahoma City Thunder's Nick Collison (L-R), Russell Westbrook, and Kevin Durant react during overtime of Game 4 of the NBA Western Conference Final basketball playoff against the Dallas Mavericks in Oklahoma City, Oklahoma May 23, 2011. REUTERS

OKLAHOMA CITY, May 23 - Dallas produced a remarkable comeback to beat the Oklahoma City Thunder 112-105 in overtime with German Dirk Nowitzki making 40 points and pushing the Mavericks within one win of clinching a place in the NBA finals.

The Mavericks lead the series 3-1 and can secure a place in the championship game against the Miami Heat or the Chicago Bulls, with a victory in game five in Dallas on Wednesday.

Dallas had not lead at any stage in regulation and were 15 points down with just over four and a half minutes remaining in the fourth quarter.

The Thunder, however, lost their way on offense after James Harden fouled out.

Dallas then finished with a 17-2 run with Nowitzki producing two free throws in the final seven seconds as the game was tied at 101-101 after regulation.

In overtime Dallas took control over a demoralized Thunder who will now have to rediscover their spirit for Wednesday or see their dream end.

Nowitzki's 40 point performance was his second in this series and included 14 on 15 free throws.