It took 27 games for San Diego State to finally falter. The Aztecs started the season 26-0 and were the nation's last remaining unbeaten team in Division I.

That changed Saturday. SDSU's record is now 26-1.

UNLV, a .500 team with no shot of making the NCAA tournament as an at-large bid, handed San Diego State its first loss of the 2019-20 season, fending off a furious rally to secure the 66-63 upset. The Rebels held SDSU's usually hot-shooting offense to just 30% shooting from three-point range. Leading scorer Malachi Flynn only managed 4-for-13 from distance, scoring most of his 24 pointslate including two threes in the final 2:40.

Elijah Mitrou-Long led UNLV with 19 points off the bench — including four game-clinching free throws in the final seconds. Amauri Hardy chipped in with 17 points in one of the biggest upsets of the entire season. UNLV led by 14 at halftime and by double digits with four minutes left before the Aztecs started to rally in the final minutes for a down-to-the-wire finish.

The Aztecs, ranked No. 4 in the Coaches Poll, could be in jeopardy of losing out on an NCAA tournament No. 1 seed thanks to their first résumé blemish.

Although SDSU has a much better record and NET score than projected No. 2 seeds Maryland and Duke, Saturday's setback at home qualifies as a Quadrant 3 (home games against opponents ranked 76-160 in NCAA's NET rating) loss. And SDSU only has four Quadrant 1 (top 30 home, top 75 away) wins as compared to Maryland's six with no bad losses. Fellow No. 2 seeds Duke, Dayton and Florida State also only have four Quad 1 wins.

The Aztecs have taken the college basketball world by storm after getting zero votes in the preseason Coaches Poll. Transfers Flynn (Washington State), Yanni Wetzell (Vanderbilt), and KJ Feagin (Santa Clara) have all fueled a storybook season.

There have been 19 unbeaten teams to enter the NCAA tournament, and it appeared SDSU was poised to do so after dominating opponents in the Mountain West. UNLV entered the game as 15½-point underdogs before pulling off the unthinkable Saturday.

After San Diego State beat New Mexico to clinch the Mountain West Conference title weeks before the regular season ended, coach Brian Dutcher said he told his team "Now we have to get greedy and try to win them all."

Greed won't be a concern anymore.