Ron Lewis revived the Buckeyes' national championship hopes with a long 3-pointer with two seconds left to force overtime, then Mike Conley Jr. dominated the extra period for a 78-71 victory over Xavier in a second-round South Regional game today.

The Buckeyes' rally from an 11-point deficit in regulation ensured the Oden era will last at least one more game.

Oden, the most coveted player to enter college in years, figures to be the first pick in the NBA whenever he decides to go pro. A decision on where the freshman intends to play next winter isn't expected until after the season ends.

The Buckeyes are fortunate that time hasn't already come.

''I'm hoping we can learn from this game and know we can't just play around with teams in the first half,'' Oden said. ''Then the second half we've got to come at them and keep coming until the game is over.''

Ohio State trailed 55-44 with 7½ minutes left, and was still down 61-52 with 2:54 left. When Oden fouled out with a hard shove after Xavier's Justin Cage rebounded an errant Buckeyes shots in the final 10 seconds, they looked lost.

Cage then made of one of two foul shots with 9.3 seconds left for a 62-59 lead, giving Ohio State its last chance. Lewis came down and, with two defenders flying at him, swished the tying 3-pointer from several feet beyond the arc.

''I was just trying to get an open look. I told Mike before we even left the huddle, 'Just give me the ball.' That's what he did. He found me,'' Lewis said.

''That's what I love about this team,'' Ohio State coach Thad Matta said. ''They give you, as a coach, a lot of confidence. I kept telling them, keep your confidence and make plays, and they did.''

With Oden on the bench, fellow freshman — and high school teammate — Conley took over. He scored 11 points in overtime and the Buckeyes (32-3) were never threatened again in winning their 19th straight game.

The Buckeyes, who finished No. 1 in the final Associated Press poll, advanced to the round of 16 for the first time since they went to the Final Four in 1999 — an appearance later vacated because of NCAA probation. They will play the winner of tomorrow's game between Tennessee and Virginia.