DALLAS -- The Dallas Mavericks still can't stop Phoenix's inside-and-outside playoff combination, even with Amare Stoudemire on the bench with an injury this year.

Boris Diaw took over Stoudemire's starring role from last postseason, scoring 34 points -- including a turnaround 7-footer with 0.5 seconds left -- to cap a tremendous closing finish, sending the Suns past the Mavs 121-118 Wednesday night in a thrilling, fast-paced start to the Western Conference finals.

Steve Nash remained the outside force, scoring 27 points and adding 16 assists, the most by anyone this postseason and one shy of his career playoff high.

Devin Harris scored a career-high 30 points for Dallas and Dirk Nowitzki had 26 points and 19 rebounds for the Mavs, who host Game 2 on Friday night.