Less than 48 hours after a shocking loss at Grambling, Tad Boyle's Colorado Buffaloes bounced back in a big way Sunday with a 78-66 win over No. 11 Tennessee at Bridgestone Arena.

The Buffs improved to 2-1 with the win on what was technically a neutral floor but in front of a crowd of 12,482 dominated by Tennessee fans. They saw their Volunteers fall to 1-1.

The victory was Colorado's first over a ranked team away from home since beating No. 13 Dayton early in the 2019-20 season. It was also the highest-ranked team CU has beaten away from home since the Buffs beat No. 6 Missouri in the 1990 Big Eight tournament.

Sophomore guard KJ Simpson led Colorado with a 23-point, 10-rebound double-double — both career highs — while Tristan da Silva added 14 points and J'Vonne Hadley had five points and 10 rebounds.

Josiah-Jordan James and Tyreke Key each scored 15 for the Volunteers.

The Buffs were a completely different team than the bunch that dropped an 83-74 decision at Grambling in a lackluster performance Friday. CU played with energy from the outset and trailed by two at the half, then turned on the offensive jets and kept the defensive pressure on after halftime to secure the win. Colorado took a 39-38 lead on a Jalen Gabbidon 3-pointer early in the second half and never trailed again. CU built its cushion to as much as 14 down the stretch.

After allowing Grambling to shoot 50 percent from the floor, the Buffs held Tennessee to 25 percent shooting (16-for-63), including a 10-for-37 effort from 3-point range. The Buffs also had a dominant 47-38 edge on the boards and while they committed 19 turnovers, they actually outscored Tennessee in points off turnovers, 16-14.

Colorado's big edge came in the paint, where the Buffs outscored the Vols 34-10. CU's bench also outscored their Tennessee counterparts, 52-34.

"We really got after them defensively," Boyle said. "The grit and toughness our guys showed was great. We beat a very good basketball team."

HOW IT HAPPENED: Colorado trailed by two at the half before using an 8-0 run early in the second period to take a 42-38 lead. Gabbidon and Julian Hammond III both hit 3-pointers to fuel the surge.

The Buffs then slowly built their edge, getting solid play on the defensive end and good ball movement on offense. An Ethan Wright 3-pointer pushed the Buffs' edge to 49-45 with just under 13 minutes to play and two Simpson free throws four minutes later gave Colorado a 55-48 edge.

Simpson scored 15 of his points in the second half while da Silva had 10 of his after intermission.

"A lot of us were disappointed after Grambling," Simpson said. "Coach was really disappointed. My job as a leader of this team is to set the tone. It's all about a tough mindset."

The Buffs continued to maintain their defensive pressure over the final minutes. With eight minutes remaining, Colorado held a 57-50 edge and Tennessee was just 5-for-20 from the floor in the period.

After a timeout, the Buffs' offense truly caught fire, putting together a 9-0 run to build a 14-point lead.

Simpson started the run with a pair of layups. Hammond followed with another drive to the bucket. Da Silva then drained a 3-pointer from the top off an assist from Lawson Lovering to give Colorado a 66-52 cushion with just under five minutes to play.

"That three was really the dagger," Boyle said. 

It was also enough to elicit a timeout from Tennessee coach Rick Barnes. But the Vols couldn't come back after the break as CU kept up the pressure over the final minutes. The Buffs built their lead to 69-55 on another da Silva 3-pointer with 2:40 to play, then hit seven free throws in the final minutes to keep Tennessee at bay and collect the win.

Simpson had five free throws in the closing two minutes.

"He's just such an aggressive player," Boyle said. "We're trying to let him evolve into the point guard role. He's a competitor and a winner. He hit the front end of those one-and-ones to put it away down the stretch."

Along with stifling Tennessee's offense, the Buffs held a commanding 46-37 edge on the boards.

The Buffs trailed by just two at intermission, 34-32, after an excellent first half on the defensive end. CU held Tennessee to 23 percent shooting from the floor (6-for-26) and also held a 24-21 edge on the boards.

But the Vols managed to maintain their lead for most of the half thanks to a steady parade to the free throw line. Tennessee shot 21 free throws in the opening half and made 17 while the Buffs shot just eight freebies and made five.

"Free throws kept them in the game," Boyle said. "That and our turnovers."

Colorado had its own issues on offense in the first period, enduring a 4:40 scoreless stretch midway through the half that saw CU miss 12 straight field goal attempts.

But the Buffs kept themselves in the game by playing good defense and hitting the boards. With 6:44 left in the half, UT built its biggest lead of the half, a 26-18 edge.

But the Buffs responded by holding the Vols to 2-for-18 shooting from the floor in the final minutes of the half and getting a boost on the offensive end from Lawson Lovering and Hadley. Both hit three-point plays to pull the Buffs to within 27-26 before a Nique Clifford free throw tied the game at 27.

The Vols finally ended their field goal drought with a 3-pointer late in the half but the Buffs responded with a Simpson trey at the buzzer to pull within two, 34-32, at the break.

TURNING POINT: After managing to stay within striking range in the first half, the Buffs used an 8-0 run early in the second period to take a 42-38 lead and Colorado never trailed again.

WHAT IT MEANS: The win against a ranked team away from home will be a huge boost to Colorado's NCAA NET ratings while also greatly easing the sting of Friday's surprising loss at Grambling.

NEW STARTING LINEUP: After Friday's game, Boyle shook up his starting lineup, sending Lawson Lovering, Ethan Wright, Javon Ruffin, Jalen Gabbidon and Luke O'Brien onto the floor to start the game.

"I just felt like we had to send a message to the guys that start the game, that they have a responsibility to bring energy and be ready to roll," Boyle said. "It was also a message to those guys on the bench that hey, you better be ready." 

The starting lineup kept CU in the game early, as Colorado trailed just 10-9 when Boyle inserted his regulars roughly five minutes into the first half.

CU STANDOUTS: Sophomore KJ Simpson had his best game as a Buff, notching his first double-double with career highs in points (23) and rebounds (10) … Tristan da Silva played excellent post defense against Tennessee's bigs and finished with 14 points … J'Vonne Hadley had five points and 10 rebounds … Sophomore big man Lawson Lovering continues to make excellent progress. Lovering had a key role in CU's post defense, helping limit Tennessee to 10 points in the paint, and he finished with five rebounds, three points and two assists.

KEY STATISTICS: The Buffs held Tennessee to 25 percent shooting (16-for-63), including 10-for-37 from 3-point range … Colorado had a dominant 47-38 edge on the boards … CU outscored Tennessee 34-10 in the paint … Colorado also limited the Vols to just three fast break points.

QUOTEWORTHY: "Let's learn from the last 48 hours. It's all about our mindset. Our mindset was where it needed to be today." — CU head coach Tad Boyle

NEXT UP: The Buffs open play Thursday in the Myrtle Beach Invitational in Conway, S.C., with an 11:30 a.m. (MT) game against UMass (ESPNU). The Buffs play again in the tourney on Friday and Sunday against opponents yet to be determined.