San Diego, Calif. » As usual, the air was warm and the sun shining brightly outside the arena where the Utah Utes played San Diego State on Saturday.

Inside, things were a lot gloomier.

Even though they were riding a four-game winning streak, the Utes stumbled out to one of their worst starts of the season against one of the nation's stingiest defenses, and never could fully recover amid some uncharacteristically bad shooting to avoid a 72-63 loss -- their third straight at Cox Arena. The Utes had never lost three in a row there, and they fell for the 20th time in their last 26 league road games overall.

"That's as good a defensive team as we've played," coach Jim Boylen said.

Maybe a championship contender, in fact.

Air Force's Jeff Reynolds last week called the 12-3 Aztecs the best team in the league, and they looked the part in winning their fifth straight game.

With their long and athletic pressure defense, they harassed the 10-6 Utes into an awful start -- just three baskets and five points in the first 8 ½ minutes, when they fell behind by 11 -- and kept them from ever climbing closer than four.

Time after time, the Aztecs forced the Utes into careless turnovers or errant shots, frequently turning them into fast-break lay-ups or drives to the hoop. The Utes shot 6-for-23 from three-point range, too, and seemed to give up big plays every time they scratched their way within shouting distance.

"We just didn't come out with enough energy or toughness to execute offensively or keep them off the offensive glass," Utah's Shaun Green said.

San Diego State's Ryan Amoroso was the biggest beneficiary, scoring most of his season-high 17 points down low (though his two three-pointers didn't hurt) while helping keep Utah center Luke Nevill from killing the Aztecs. Nevill finished with 17 points and seven rebounds, but didn't really affect the game that much after dominating Wyoming and LSU.

"We bumped him and got him off the block and made it hard for him to feel comfortable," coach Steve Fisher said.

Even Boylen had a rough night, getting whistled for a technical foul for walking onto the court to contest a no-call after having been warned about doing that earlier. He already had been a target for the rowdy fans for appearing to get in the way of a ball that went out of bounds off the Aztecs, and the ensuing free throws -- the Aztecs hit one of the technicals, then two for the foul on San Diego State's Lorrenzo Wade that began the sequence and sprained Wade's shoulder -- pushed the lead to 60-48 with 5:11 remaining.

Later, the Aztecs made eight straight free throws in the final 90 seconds to seal it.

"They're a good team," Boylen said. "I wasn't really happy with the way we played, [but] I think they had something to do with it."

mcl@sltrib.com