SAN DIEGO — San Diego State felt just a bit too comfortable after building a 19-point lead against Air Force with less than two minutes left in the first half.
By late in the game, the lead was down to just two points, and in the closing minute, one point.
But Winston Shepard helped rescue the Aztecs by scoring their final five points and SDSU held on to beat the Falcons 53-49 Wednesday in a Mountain West Conference opener.
"Can you find fault with a lot that happened in the second half? I'm m sure you can," coach Steve Fisher said. "But good teams find ways to win.
"If we want to be really, really good, we've got to find ways to have a 31-12 lead not dissipate and it started ever so slightly at the end of the half."
JJ O'Brien scored 10 points and Aqeel Quinn and Matt Shrigley nine each for SDSU (11-3, 1-0), the defending regular-season champion which won its eighth straight conference opener. SDSU has won four straight against Air Force.
The Aztecs led by 19 with less than two minutes to go in the first half but Air Force came on strong in the second half and pulled within two points three times.
After Hayden Graham made a layup to pull Air Force to 48-46 with 2:58 left, Shepard — who had missed 10 of his first 11 shots — made a clutch jumper from the baseline.
Air Force answered with a layup by Justin Hammonds with 1:35 left.
Each team missed a shot before Air Force's Max Yon was fouled and made the front end of a one-and-one to make it 50-49, but missed the second shot.
Shepard rebounded the miss, was fouled and made the front end of a one-and-one for a two-point lead but missed the second. Marek Olesinski rebounded and Air Force played for a final shot but Zach Kocur couldn't handle a pass from Max Yon and lost it out of bounds with four seconds left.
"We said, 'Let's be in it to win it' and we were," Air Force coach Dave Pilipovich said. "It's hard. Our guys are hurting."
Shepard was fouled and hit both shots with 3.2 seconds left.
"We started the second half slow," O'Brien said. "I think maybe we got comfortable with the lead we had coming out of halftime. Air Force knew if they came out hot they'd have a chance and they did. They got going. It took some resilience to pull our game back together and pull out a win."
Pilipovich said the Falcons took care of the ball better in the second half and the Aztecs didn't press as much, "which gave us a better flow to play offense.
"We have unbelievable respect for them but we were playing on our heels in the first half," Pilipovich said. "In the second half we finally said, 'OK guys, we're good enough to do this.' We played like a team that we know we can and we competed in the second half. I'm proud of our effort."
Yon scored 15 and Kamryn Williams 11 for Air Force (7-5, 0-1).
Air Force outscored SDSU 15-4 to open the second half, including a 3-pointer and two free throws by Olesinski. A three-point play by Williams, who suffered a potentially season-ending Achilles injury late in the game, pulled the Falcons to 37-34 with 15:07 left.
SDSU blunted that run with a layup by O'Brien and a jumper by Quinn before Kocur made a layup. Quinn hit a 3-pointer with 11:50 left to give SDSU a 44-34 lead.
The Aztecs had a 12-0 run in outscoring the Falcons 23-11 during the last 10 minutes of the first half.
The Aztecs' biggest lead was 31-12 after Shrigley's third 3-pointer of the half, with 1:57 left.
SDSU led 33-19 at halftime
Aztecs senior forward Dwayne Polee II missed his second straight game since collapsing during a game against UC Riverside on Dec. 22. The Aztecs didn't have a medical update on Polee.
The Aztecs, who have had a miserable year shooting, made just 32 percent (8 of 25) of their shots from the field in the second half and finished at 36.1 percent (22 of 61). They made only 4 of 21 3-pointers, or 19 percent.
"You've seen us miss shots before," Fisher said. "But when you miss shots you've got to guard better and I know they made five straight possessions for points and you can't let that happen. To some degree they made it happen and to some degree we participated in the happening. We missed quite a few good shots."
Air Force: The Falcons had won four straight conference openers coming in.
San Diego: The Aztecs have claimed at least a share of three of the last four regular-season conference titles.
Air Force visits Nevada on Saturday.
San Diego hosts New Mexico on Jan. 7.