Birch recorded his seventh double-double in nine games with 16 points and 10 rebounds, and added six blocks. It wasn't enough to make up for the loss of Smith, the NCAA's fourth highest rebounder with 11 per game, who missed the game due to a concussion. UNLV fell 73-64 to No. 10 San Diego State on Wednesday night.
"I knew they would play hard, I knew they would compete," San Diego State coach Steve Fisher said. "They made it hard on us, they made four out of six 3-pointers in the first half, and Birch did what he did in our place. He wouldn't let us come to the rim without him rejecting a shot."
"This was from wire to wire a really tough game by two good teams. We got our little spurt at the end of the game. This was a one-possession game, and we made some free throws, they missed some shots."
Freshman Christian Wood filled Smith's spot in the lineup, and scored eight points in a season-high 30 minutes. Wood also grabbed seven rebounds, second on UNLV after only Birch.
Despite leading throughout the game, UNLV (19-11, 10-7 Mountain West) struggled down the stretch, shooting 3-of-15 to end the game, including an 11-minute stretch with only one field goal.
UNLV's leading scorer Bryce Dejean-Jones finished the game 1-for-7 from the field for seven points and three turnovers. Point guard Deville Smith missed all five of his shots and turned the ball over a team-high seven times.
San Diego State (26-3, 15-2) closed the game on a 13-2 run over the final 3:04 to seal its 26th victory of the season, matching the second-highest single-season total in school history. The Aztecs also won a school-record 15th conference game of the season, breaking the previous mark of 14, set in 2010-11.
"We went in with a lot of confidence we could win and just didn't quite make enough plays down the stretch," UNLV coach Dave Rice said.
San Diego State, which has now won eight of its last 11 against the Rebels, finished 27-for-63 from the field, including 6 of 14 from 3-point range. After falling behind 62-61 with 3:23 left in the game, Xavier Thames completed a three-point play to ignite the Aztecs' final scoring spree.
"X is a winner; X is a fierce competitor," Fisher said. "He can play, and he can make plays for others and he did that again tonight. He wants to win desperately."
After Jelan Kendrick's 3-pointer gave the Rebels a 50-45 lead with 11:38 left in the game, the Aztecs' full-court press stymied UNLV the rest of the way, as it managed just two more field goals.
"We needed to buckle down and get stops," Thames said. "Our offense was pretty good all game, minus the turnovers, so we just needed to get stops."
The Aztecs, who are 12-2 away from home, are now 11-4 inside the Thomas and Mack Center since the 2010 Mountain West Tournament. This year's tournament begins March 12 at the T&M.
Fisher has been the head coach for 19 of San Diego State's 23 all-time victories against UNLV. The Aztecs were 4-17 against UNLV prior to Fisher taking over as coach of the Aztecs.