Jahmai Mashack started flexing at the free-throw line and didn't stop until he was in the Tennessee basketball huddle on the other end of the court.

Mashack earned every second after making the hustle play at the fulcrum of a critical ranked win for the Vols.

He scrapped and willed his way to an offensive rebound and smartly popped the second-chance opportunity to Dalton Knecht, who swished a 3-pointer to send a sold-out crowd into glee and Mashack into the flexing frenzy.

"What Jahmai does wins basketball games for you," Vols coach Rick Barnes said. "He had a lot to do today with what went on out there for us to win this game.”

Mashack only did one thing for Tennessee on Saturday, but that one thing means everything: The junior guard was his statsheet-stuffing, do-it-all-well self to give the No. 13 Vols (6-3) a necessary boost to an 86-79 win against No. 18 Illinois (7-2) at Thompson-Boling Arena at Food City Center.

What Jahmai Mashack liked most about his performance against Illinois

Mashack had already warmed up his flexing celebration Saturday. He unleashed it earlier after relentless defense on Illinois guard Terrence Shannon Jr. led to an attempted ball screen to open Shannon that turned into a foul for an illegal screen.

And that is what Mashack was most proud of as he frustrated Shannon and pushed Illinois to look for other options.

"It seemed like they kind of got away from (him) and they tried to run through somebody else," Mashack said. "Plays like that are probably something a lot of people don't notice."

Mashack has long excelled at the unpretty and unnoticeable, taking the utmost pride in it. He rebounds hard as a 6-foot-4 guard. He takes on any defensive challenge, which included dealing with Purdue 7-4 center Zach Edey in the Maui Invitational. He shut down Alabama star and No. 2 NBA Draft pick Brandon Miller last season. He's unbothered.

The Mashack-led Vols made life hard on Shannon, who averaged 20.3 points entering Saturday. He got to 22 thanks to a flurry of points in the final minute. It took him 16 field-goal attempts and he was 1-for-6 on 3-pointers.

Vols assistant coach Rod Clark stated the obvious Friday: Mashack covets seeing an opponent who averages a lot of points and wants a crack at guarding him. Mashack said he believed Shannon was Illinois' leading scorer. He played like he knew that.

“I thought Jahmai today played his role to the hilt," Barnes said. "The fact is, his role, what Jahmai does, his role is as important as anybody on the team."

How Jahmai Mashack is an offensive chameleon

Knecht had missed a midrange jumper and thought he was fouled. He was asking for the call as Mashack ensured the possession continued, finding Knecht open for a 3-pointer to end a 10-0 run to put UT ahead 50-44.

"He embraces it and when he does that, he is a weapon," said Barnes, whose Vols host Georgia Southern on Tuesday (7 p.m. ET, SEC Network).

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Mashack's role on offense has morphed through his career. He has played all guard positions, including point guard. He gets minutes at the four. He's versatile, flexible and amenable to change. He's experiencing it again as Tennessee has a deeper, more talented well of guards than in the past.

"I have the confidence that I can adjust," Mashack said. "Big thing for me and I think the main thing that if you think of Jahmai Mashack, you think of resilience. I have that through and through."

Because of that, Mashack is essentially perfect for the Vols. He doesn't need shots to affect the game. He'll create his own plays and set up others. He did so Saturday with his kickout to Knecht. He had a timely baseline drive and got an assist on a Santiago Vescovi 3-pointer. He dashed in for a mini-hook. He drew a team-high five fouls and had three assists. He had nine points, five of which were on free throws. He made both his field-goal attempts.

He played the fewest minutes (14:38) of UT's eight against Illinois and had the highest plus-minus (+13). That's Mashack's sweet spot. He offered the thesis of his basketball abilities afterward: The Vols can put Mashack anywhere and he will figure it out and the team will be successful.

He did it Saturday, playing a complete game that completely changed the game.

Mike Wilson covers University of Tennessee athletics. Email him at michael.wilson@knoxnews.com and follow him on Twitter @ByMikeWilson. If you enjoy Mike’s coverage, consider a digital subscription that will allow you access to all of it

This article originally appeared on Knoxville News Sentinel: Jahmai Mashack had complete game for Tennessee basketball vs Illinois