Provo • It was pretty hard.

It was actually really, really hard, but Khyiris Tonga knew he had to stop his McDonald’s runs.

Tonga’s weight has been a recurring subject as coaches talked to him about his dreams of playing professional football — a goal Tonga has said he hopes to achieve after his junior season.

But now that Tonga’s weight is just shy of the magical number he wanted to hit (he previously said he wanted to weigh in at 319 pounds before training camp started July 30 and is currently listed at 321 pounds), he’s putting up other magical numbers.

Tonga had a breakout game against No. 24 USC last weekend, when the Cougars defeated the Trojans 30-27 in overtime.

“We knew USC was going to be a great team — their offense, their defense, everyone on their team,” Tonga said. “Our mentality was just to go out just to play, have fun, be disciplined, make some plays and I feel like we did good on that.”

The defensive lineman had four solo tackles, a sack for six yards lost and two pass breakups.

Fellow defensive lineman Lorenzo Fauatea said the team has come to expect that type of performance from Tonga, and he has come to look up to his teammate as a mentor.

When it comes to watching film, the pair usually sit together.

“Sometimes, we'll joke around with each other, but most of the time we're serious,” Fauatea said. “He'll give me critiques on some things and I'll give him critiques on some things. Just having Khyiris around is good. It's good for me that I can see and learn from an upperclassman.”

Even though Tonga had a standout game, his favorite moment wasn’t one he was involved in.

“When Dayan (Ghanwoloku) got the pick to end the game, that was my favorite moment,” Tonga said. “It was fun for me.”

BYU’s defense has been a talking point of sorts after forcing overtime at Tennessee and against USC, beating both programs.

Coach Kalani Sitake said there’s so many things his defense can do with defensive formations because of the athletes on the team. And he also heaped praise of defensive line coach Ilaisa Tuiaki.

The defense went without Zayne Anderson and Sawyer Powell, and lost Keenan Pili early in the game, against USC. Yet, they still gave the Trojans a hard time and shut down USC's passing game.

When it comes to the potential Sitake sees in Tonga, Fauatea and the rest of his defensive line, there’s plenty room for growth, but is pleased with their work ethic.

“Those guys are athletic and they can move and they’re relentless and they have a good coach,” Sitake said. “He does an amazing job getting them ready, but I’ve been really pleased with those guys — their approach to the game and the challenges we give them.”

The challenge for Tonga isn’t done, not with nine games left before he pursues that NFL dream.

When asked what fans can expect to see from him going forward, he said: “I think just more dominance and more discipline.”

And don’t expect to run into him at a McDonald’s anytime soon.