Colonials forward Yuta Watanabe celebrates a blocked shot during the second half of George Washington’s 73-68 victory over No. 6 Virginia. (Toni L. Sandys/The Washington Post)

Well before the George Washington men’s basketball team tipped off against Virginia on Monday night, the atmosphere at Smith Center was more akin to the NCAA tournament than the second game of the regular season. Colonials fans made it so in part with chants of “overrated” directed at the sixth-ranked Cavaliers during warmups.

Then GW players rewarded their faithful with a 73-68 win that concluded with fans storming the court in Foggy Bottom. Many students hugged starting guard Patricio Garino, and with good reason. The Argentine senior finished with 18 points on 7-for-8 shooting and triggered a decisive 10-0 run in the second half.

It’s the third straight year the Colonials have beaten a ranked opponent. Last season, they toppled then-No. 11 Wichita State, and in December 2013 they beat then-No. 20 Creighton.

“This is definitely memorable for life,” Garino said. “I think beating ranked teams three years in a row is a big deal, but honestly we’re not surprised. We know that we have the personnel. We have confidence. I think we’re playing great basketball. All the credit to Virginia. They deserve to be top six, but I think we’re up there.”

Playing in front of a sellout crowd of 5,025, Garino put the Colonials (2-0) ahead to stay with a three-point play with 8 minutes 6 seconds left in the game as part of seven in a row on his own. His offensive rebound and putback expanded the lead to 59-55, and junior forward Tyler Cavanaugh’s layup to make it 61-55 came courtesy of Garino’s pass. Cavanaugh, a transfer from Wake Forest, also had 18 points.

The Colonials went 15 for 17 on free throws in the second half, a departure from last season when misses at the line doomed them in several games. Rebounding also factored in significantly for GW, which held a 37-33 advantage despite 6-foot-10 forward Kevin Larsen yielding two inches to his defensive assignment, Virginia center Mike Tobey.

Larsen more than held his own, but not necessarily in the scoring column. The senior instead showed why Coach Mike Lonergan calls Larsen the most skilled passing big man he has worked with in his career, collecting a game-high five assists in addition to nine points and seven rebounds, redemption for one of the worst showings of his career in last year’s 59-42 loss in Charlottesville.

“It was a full team effort, and the crowd was great,” Cavanaugh said. “They gave us energy. That was my first time playing in front of a real packed Smith Center, and it was just amazing to have that type of feel. We beat a very good team tonight, and the credit goes to them as well.”

After trailing for much of the first half, Virginia (1-1) went back in front 40-39 with 15:47 left by scoring six consecutive points. The go-ahead three-pointer came from London Perrantes. It was the first points of the game for the junior guard who averaged 6.4 points and 4.6 assists on the way to being named honorable mention all-ACC last season.

But just when it appeared the Cavaliers were ready to assume control as they did in the second half last season, GW countered with Garino’s three-pointer to reclaim the lead. Malcolm Brogdon answered with a jumper for Virginia before GW reeled off six in a row, beginning with Cavanaugh’s layup. Larsen got a layup to drop soon after, and Garino’s offensive rebound and putback made it 48-42 with 12:45 to play.

The game was tied for the last time when Darius Thompson made a three-pointer to trim the deficit to 52-50 and Brogdon added a layup with 9:04 to play.

The Colonials rallied from an early deficit to take a 31-22 first-half lead courtesy of a 9-2 surge that ended with Garino’s steal near midcourt and fast-break dunk. Included in GW’s push was point guard Joe McDonald’s second three-pointer of an assist from Larsen that energized the crowd, followed by backup guard Paul Jorgensen’s driving layup.

Lonergan used Jorgensen as part of a smaller lineup with elevated three-point pop. Joining the sophomore during that stretch was, among others, Alex Mitola and Matt Hart, both reserves. Mitola is a graduate transfer from Dartmouth, where he scored 1,000 points over his career. Hart is a junior transfer from Hamilton eligible after sitting out last season.

Brogdon scored a game-high 28 points, including 20 in the second half, but the Cavaliers were unable to overcome 40.3 percent shooting. One of the top defensive teams in the country also permitted GW to shoot 50 percent in the first half.

“I don’t think it was the atmosphere that got to us,” Brogdon said. “It was our defense. What we pride ourselves on the most, our foundation, really let us down tonight.”