The Panthers won the best-of-three series 2-1, capturing the final two games on their home court after losing the opener by a point in Washington.
The deciding game was deadlocked with 14:24 to play after Washington State's D.J. Shelton scored on a layup. Pittsburgh then went on its key surge, with Zanna scoring six out of the 12 points. His dunk with 9:25 remaining gave the Panthers a 56-46 lead.
Tray Woodall led Pittsburgh (22-17) with 17 points and Lamar Patterson had 14. The Panthers shot 50 percent from the field with Zanna making 5-of-6 while scoring 12 points.
Reggie Moore had 18 for the Cougars (19-18).
Pittsburgh joined Stanford and Mercer as winners of post-season national tournaments. Stanford overwhelmed Minnesota Thursday to capture the NIT and Mercer defeated Utah State to win the CollegeInsider.com tourney.
The NCAA Tournament comes to a close during the next three days, with Louisville meeting Kentucky and Kansas facing Ohio State in Saturday's semifinals. The winners will meet Monday night for the championship.
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