Teasley helped the Sparks win their second consecutive title by hitting a series-winning three-pointer in the final seconds.
He hit back-to-back 3-pointers in the final 33 seconds to cut a 22-point deficit to 16.
Postell hit three of four foul shots in the last 21.4 seconds, and everyone played defense.
But the Irish (16-5) chilled the comeback on the free-throw line, hitting seven of eight in the final 90 seconds.
The Tigers (25-8) let Connecticut (15-12) hit three 3-pointers in the final 50 seconds to force the overtime.
Goheen hit two three-point shots in the last 10 seconds to tie the game in regulation and send it to overtime.
Kidd hit two 3-pointers in the final 49 seconds to cut the deficit to 86-83 with 23.4 seconds left.
But Webber also scored 11 points in that quarter, no basket as crucial as the one he hit in the final 3.4 seconds.
White looked comfortable hitting a 15-foot jumper in the first 90 seconds, helping the Rebels to an 8-2 lead.
Western Carolina had one shot to win and another to tie; both attempts hit the back of the rim in the final seconds.