TUCSON, Ariz. -- As officials studied the television monitor at the end of regulation to determine if Colorado won the game, Arizona coach Sean Miller huddled his team near the bench, presumably to prepare for overtime.
"I was sending the officials a subliminal message that I knew the shot was no good," Miller said with a smile after the third-ranked Wildcats recorded a 92-83 overtime victory. "It was an all an act."
For three minutes, nobody in McKale Center knew whether the game had ended on a banked 3-point shot by Sabatino Chen at the buzzer. The shot, ruled good on the court, was waved off in a call that came down to perhaps a tenth of a second and a matter of fingertips.
Having rallied from a 16-point second-half deficit, Arizona (13-0) then pulled away in overtime to remain one of four unbeaten teams in college basketball. The others are Duke, Michigan and Wyoming.
"Once we got it to overtime, I knew we were going to win the game," Arizona senior guard Kevin Parrom said. "Simple as that. The game was over."
Colorado coach Tad Boyle ended the night fuming over the reversal. He told ESPN.com by phone, "Get rid of instant replay. In basketball, football, human error is part of our game. If human error is part of the game, let the officials call the game. Players, coaches and officials will make mistakes. It's part of the game.
"We spend all this money on replays and we still can't get it right. Get rid of it."
Colorado, which made 10 of 15 3-point shots in regulation, went 0-for-6 from beyond the arc in overtime. The Buffs also hurt themselves by hitting only four of 12 free throws after there were two minutes left in regulation.
"In overtime, we battled for the first few minutes, and then we couldn't get stops and had trouble scoring," Boyle said.
Arizona senior point guard Mark Lyons scored 24 points, including the tying free throws late in regulation.
The Buffaloes (10-3) led by 16 points with 12:42 to play. Arizona whittled the lead from there but still trailed 78-70 with 1:44 to go.
The Wildcats finished regulation on a 10-2 run, helped by two missed free throws by Colorado's Jeremy Adams with 18 seconds to play. Lyons tied the game with two foul shots with 9.2 seconds left.
Chen had a chance to even the score with 1:28 left in overtime, but he missed two free throws. Lyons converted a three-point play on the other end to give Arizona an 88-83 lead with 1:09 to go, and the Buffaloes would get no closer.
"It's disappointing because our team played well enough to win," Boyle said. "I credit Arizona, and I'm not taking anything away from them. They did what they had to do to win it down the stretch in overtime."
Parrom helped fuel Arizona's comeback with 16 points and eight rebounds off the bench.
Sophomore guard Askia Booker scored 18 points to lead five Colorado players in double figures. Chen, a senior guard, scored a career-high 15.
Colorado was hot from the start, hitting five of its first six shots from the field and pulling away from Arizona for much of the first half. The Buffaloes led 34-27 at the break.
Colorado freshman forward Xavier Johnson, who entered with an average of 6.3 points per game, had a team-high 12 points at the break, having made all four of his shots from the field. He added just one point after halftime.
The Wildcats started cold in their first game since Christmas Day in Honolulu. They made only two of their first 15 shots and finished the half 7-for-27 (25.9 percent) from the field.
Colorado's biggest lead of the half came at 30-13 with 4:37 to go when Andre Roberson hit a 3-pointer as the shot clock expired. Arizona climbed back into contention by finishing the half on a 14-4 run, initially fueled by 3-pointers from Parrom and Grant Jerrett.
NOTES: The Colorado game marked Arizona's second sellout of the season at McKale Center. The other was for the game against then-fifth-ranked Florida on Dec. 5. ... The Buffs defeated Arizona in two of three games last season in their Pac-12 debut, including a 53-51 victory in the conference tournament championship game. ... The Wildcats hadn't opened conference play at home since the 2007-08 season. They improved to 13-0 in league openers at home since joining the Pac-10 for the 1978-79 season. ... The last time Colorado defeated a top-10 team on the road was Jan. 15, 1973, when it beat No. 5 Missouri 81-79 in overtime.