On third-and-25 from San Francisco's 48, Bosa pressured Jaguars quarterback Trevor Lawrence, eventually chasing him to the sideline, where he got a hand on Lawrence as the QB ducked out of bounds for a 1-yard loss.
It wasn't until the 49ers defense left the field that linebacker Fred Warner informed Bosa he had just reached 10 sacks for the first time in his young career.
"I've never gotten one like that," said Bosa, who had recorded his ninth sack two plays before. "We always watch them in the film room, and we're, like, 'Oh, man, that's B.S.'"
That sack is the only thing about Bosa's return from a devastating left knee injury that has come cheap. The No. 2 overall pick out of Ohio State in the 2019 NFL draft, Bosa returns to Ohio on Sunday to play the Cincinnati Bengals (4:25 p.m. ET, CBS) with 12 sacks, 39 tackles and 16 tackles for loss through 12 games. He's making a compelling case to land his second Pro Bowl bid and first All-Pro selection.
He's doing it a little more than a year after a Sept. 20, 2020 knee injury suffered against the New York Jets. The knee required a reconstruction of a torn anterior cruciate ligament, torn medial collateral ligament and torn lateral meniscus. It was the type of complete knee injury that has prevented players from returning to full strength and ended careers.
But this season Bosa has picked up where he left off at the end of a dominant rookie season when he had nine sacks and an interception. What's more, Bosa's production this year has come despite being doubled-teamed more than any other edge rusher in the NFL (27.3%).
"Bosa is a special player and he's just as valuable this year as he was his rookie year," coach Kyle Shanahan said. "He was the difference for us in 2019 and we missed him greatly last year. And you guys can see why again this year. I think he's getting better each week. And I think he's playing his best ball right now."
Bosa's recovery is the result of a maniacal approach to his rehab and physical conditioning with an increasingly strategic approach to pass rushing. Bosa has trimmed his weight to about 255 pounds from the 262 he played at early in 2020. Even his famously thick quadriceps are noticeably smaller.
But it might be Bosa's continued commitment to learning his craft that has been most imperative to his huge season.
"Bosa is kind of quiet in general, but when you get him talking a little bit and he starts talking about techniques and stuff like that, there's a lot going on up there," quarterback Jimmy Garoppolo said. "I mean, he really is breaking down the game inside and out, the pass rush, the coverage, all this stuff tied together. He's very in tune with it. When you have a guy that could do what he does and he's that tuned into the details at the same time, that makes for a special player."
Nowhere is Bosa's attention to detail more evident than in his frequent conversations with left tackle Trent Williams. Williams and Bosa are considered two of the best in the league at their respective positions and that shows up in practice battles. What can't be seen, though, are the extensive discussions between Williams and Bosa in which they pick each other's brains on what they're thinking on reps.
Shanahan is known for his attention to detail, but even he is taken aback by listening to Bosa and Williams talk about "25 different things that happened in three seconds." Bosa will grill Williams on things like hand usage, speed, specific movements, fakes and much more.
"Nick's one of the smarter players I've ever been around," Shanahan said. "He's extremely talented. But just the detail, he looks into everything. ... And you see the technical stuff that he's always on, so the more he goes against guys, the more he studies tape, not everyone's like that, but he soaks in a lot and he applies to his game, which has been real impressive."
On a recent December day, Bosa found himself reflecting on his 2021 season versus his 2019 campaign. In that rookie season, Bosa led the NFL with a whopping 102 quarterback pressures between the regular season and the playoffs. Alas, he only turned 13 of those into sacks, leaving him feeling like he left plenty more sacks on the field.
As Bosa considered why more of those pressures have turned into sacks this season, he acknowledged perhaps he had actually been overthinking things as a rookie or, as he says, "correcting things that really didn't need correcting."
"I always thought in 2019 that I needed to do more drills where I am actually taking down the quarterback and I would always think like, 'What is he going to do? What is he going to do when I get through and it's just me and him?'" Bosa said. "And it's not about me doing things differently. It's just about me playing more and it just kind of happened."