SALT LAKE CITY (AP) -- Phil Cullen didn't know the score when his shots started to fall. After he scored 11 straight points, it didn't matter.

Hanno Mottola scored 17 points and Cullen, a reserve, added all of his 11 points during a decisive second-half run as No. 19 Utah beat Colorado State 76-70 Monday night.

With the victory, the Utes (15-3, 4-0 Mountain West) extended the nation's longest home-court winning streak to 47 games.

Cullen scored 11 straight over a span of 2:09 as Utah took a 57-50 lead with 9:56 to play. He had a three-point play, hit consecutive 3-pointers and added a pair of free throws, the only Utah player to score in the spurt.

"I didn't know the score when I started taking those shots," said Cullen, who shot 0-for-6 Saturday against Wyoming. "It didn't matter. I felt real comfortable. They were shots I would have been taking anyway."

Utah coach Rick Majerus gave Cullen a green light to shoot, but he was more impressed with another strong defensive effort by the Utes.

"He's a real good shooter, but the best part about him tonight was his defense," Majerus said. "We had some defensive stops. We played hard. The offense has never meant that much to me. It's the defense that matters."

Alex Jensen scored 15 points for Utah and Tony Harvey had 10.

Ron Grady led the Rams (11-7, 1-3) with 15 points. John Sivesind and Ceedric Goodwyn each had 13 and John Ford added 12.

Colorado State came in leading the nation with 48 percent shooting from 3-point range and the Utes were ranked fifth at 41 percent. Neither team disappointed, but it was the Utah defense that took hold when needed and held on down the stretch.

"They're great 3-point shooters, the best in the country," Jensen said. "That was our focus, to shut them down. I don't think we did that, but we played well enough to win."

Cullen's run and a dunk by Gary Colbert off a Colorado State turnover made it seem the Utes would run away.

But the Rams got four easy points, all on free throws by Sivesind, to make it 59-55. Utah's Jeff Johnsen was called for a foul and Majerus received a technical for throwing items off the scorer's bench in protest.

"I don't like to get technicals," Majerus said. "I'm not proud of it. I usually don't say much. I got mad and threw a paper cup, but I didn't say a word to the referee."

The Utes settled down and pulled away on Johnsen's wide-open 3-pointer for a 66-57 lead with 4:59 remaining. Free throws by Grady and Goodwyn pulled Colorado State to 66-61 with 4:21 to play.

Harvey added another 3-pointer, Mottola banked in a 12-footer with Ford in his face and Harvey hit another pair from the line as the Utes pulled away despite missing six free throws in the final minute.

"When Cullen and Harvey started hitting those 3s, that stretched their lead and it was just something we couldn't overcome," said Colorado State coach Ritchie McKay.

Colorado State shot 51 percent for the game, the first of Utah's four conference opponents to break 40 percent. It was the fifth time in the last seven games shooting better than 50 percent but the Rams are 3-4 in those games.

"We had a sense of purpose tonight and we shot well," McKay said. "When we shoot well, we have a tendency to play better defense and hustle."

Colorado State hit 46 percent from 3-point range while Utah, coming off a season-low 39 percent shooting effort Saturday against Wyoming, made 52 percent overall and 52 percent on 3-pointers.

Utah started quick, building a 22-11 lead midway through the first half, but the Rams rallied with a 13-3 run over a 2:53 span later. Grady, Goodwyn and Aki Palmer hit 3-pointers and Sivesind scored on a tip for a 28-27 lead with 4:02 before the break.

The Utes came back to tie it at 32 at halftime.