SAN ANTONIO (AP) -- Kevin Durant scored 27 points and the Oklahoma City Thunder are on the brink of the NBA Finals, beating the San Antonio Spurs 108-103 in Game 5 on Monday night and moving within a victory of a series knockout. Russell Westbrook added 23 and the Thunder took a 3-2 lead in a wildly entertaining Western Conference finals. Looking invincible while carrying 20-win streak a week ago, the Spurs have lost three straight and are on the verge of a stunning collapse. Manu Ginobili scored 34 in a smashing return to the starting lineup, but missed the potential game-tying shot in the final seconds. Game 6 is Wednesday night in Oklahoma City, where the Thunder can punch their ticket to the NBA Finals in the place they haven't lost all postseason.