CORAL GABLES — Duke coach Mike Krzyzewski looked down his bench midway through the first half, trying to check on Nolan Smith.
Small problem: Smith wasn't there.
"That's not a good thing," Krzyzewski said.
Fortunately for No. 5 Duke, Smith returned in plenty of time.
Playing with a scratched left eye, the senior guard scored 16 of his 18 in the second half, Seth Curry added 16 points and five steals and Duke extended its ACC lead by holding off Miami 81-71 on Sunday night.
"It was closed for a while," Smith said. "I really didn't know what was going on at the time. They just numbed it up a bit at halftime. Now I feel fine."
Kyle Singler scored 14 for the Blue Devils (23-2, 10-1), who gave Krzyzewski a nifty gift on his 64th birthday. "It's unbelievable being 52," he said. "I know I look a lot older."
Miami (15-10, 4-7) was bidding for its first four-game ACC winning streak since February 2008.
"I thought our guys competed," Miami coach Frank Haith said. "Obviously, we had some breakdowns defensively and gave them some open looks. … A lot of broken plays."
SINGLETON UPDATE: FSU coach Leonard Hamilton acknowledged that top scorer and rebounder Chris Singleton, who is set for surgery today on his fractured right foot, could miss the rest of the season.
NO. 10 UCONN 75, PROVIDENCE 57: Jamal Coombs-McDaniel had 25 points to top his career high by 12, and Kemba Walker, the Big East's No. 2 scorer, had 22 for the host Huskies (19-5, 7-5).
NO. 11 G'TOWN 69, MARQUETTE 60: Chris Wright had 20 points, Austin Freeman added 17 despite limping off in the first half as the host Hoyas (20-5, 9-4 Big East) won their eighth straight game.
NO. 14 PURDUE 81, ILLINOIS 70: JaJuan Johnson had 24 points for the visiting Boilermakers (20-5, 9-3 Big Ten), who survived 28.6 percent first-half shooting.
NO. 15 ARIZONA 67, ARIZ. ST. 52: Kyle Fogg hit six 3-pointers and tied a career high with 26 points, helping the visiting Wildcats (21-4, 10-2 Pac-10) grind one out.