Both favorites playing in U.S. college basketball's national championship tournament Saturday rallied from big deficits to post stunning overtime wins and advance to the Final Four (semifinals).

The nation's top-ranked team, the University of Illinois, trailed third-seed Arizona by 15 points with four minutes left in regulation time, but came back quickly. Deron Williams hit a three-point shot to tie the game at 80 with little more than a half-minute showing on the clock. Illinois held on to win in overtime, 90-89, when Arizona missed a long shot just before the buzzer.

In another regional final, The fourth-seeded Louisville Cardinals came back from a 20-point deficit against seventh-seed West Virginia to tie the game with less than a minute to go. Louisville's defense dominated the Mountaineers in overtime for a 93-85 victory.

Louisville and Illinois will face off in a semifinal game next Saturday in St. Louis, Missouri. The other matchup will be decided Sunday when regional top seed North Carolina faces sixth-seed Wisconsin, and second-seed Kentucky meets fifth-seed Michigan State.

The national championship game is in St. Louis on April 4.

Some information for this report provided by AP.