SANTA CLARA >> Trent Williams was where he usually was, even if it was a place where offensive tackles seldom venture.

Williams, even at age 36, isn’t one to be trapped in a phone booth. He was several yards downfield after a 6-yard pass from Brock Purdy to Ricky Pearsall Jr., looking to bury someone with the 49ers trailing 28-12 in the fourth quarter. That someone was Chiefs safety Bryan Cook.

Cook took exception and threw a right hand into Williams’ helmet.

“Oooh,” Fox analyst and former quarterback Tom Brady said. “I wouldn’t take on Trent Williams. Would you?”

As so often in these skirmishes, Williams was the one who got ejected for retaliating even if he wasn’t the instigator. He was reminded of that Thursday, and showed the savvy of a 14-year-veteran who knows how the system works.

“No, I didn’t,” Williams said about who threw the first punch. “But it is what it is. I don’t want to make comments about the officials, but obviously I had questions about that.”

With the 49ers (3-4) hosting the Dallas Cowboys (3-3) Sunday night at Levi’s Stadium and two long-standing rivals looking to shed the label of underachievers as midseason approaches, it’s only natural that both teams have been taking flak from their fan base as well as the local and national media.

Williams missed all of training camp while negotiating a three-year contract extension worth $82.6 million -- the last deal he’ll probably have in his career. As an 11-time Pro Bowl selection and three-time first-team All-Pro — pretty much the consensus pick as the best left tackle in the game — Williams demanded to be paid as such.

The 49ers and Williams didn’t agree to a deal until Sept. 3, so Williams was a non-participant in the offseason program as well as camp.

A slow start for the 49ers opens up the franchise to a lot of criticism. Williams hasn’t received much of that since arriving in 2020 via trade to replace Joe Staley, simply because he has been so dominant and for the most part the 49ers have been very good.

Judging the play of offensive linemen is a tricky business for outsiders, even those educated in line play. Williams has always been at the top of pretty much any analysis, and he has unofficially (there are no official statistics for offensive linemen) allowed just one sack this season and two more from 2021 through 2023.

Williams has gotten great reviews from Pro Football Focus in both run and pass blocking since his arrival, but through seven games this season, his pass blocking ranked him 26th in terms of “pass blocking win rate” with 22 pressures allowed in 261 snaps.

Any suggestion Williams is slipping is quickly rejected by Chris Foerster, the 49ers’ line coach and run game coordinator whose relationship with the star tackle dates back to his young days with Washington in 2010.

“He’s been playing as well as he’s ever played,” Foerster said. “Some things are actually better than a year ago. And it’s funny because he missed camp. It kind of bothers me.”

Williams is consistently one of the best and most expansive interviews on the 49ers, insightful and colorful especially when discussing his teammates. He is less willing to take a deep dive into his own successes.

“I’m just focused on trying to get better in the present tense,” Williams said. “I’ll let Coach talk about the product he sees. I’ll rely on him to coach me up and help me get better. My focus is on trying to get better for this team and get some wins.”

Tight end George Kittle, on record as saying Williams is one of the best football players he has ever seen — maybe the best — hasn’t seen any slippage.

“I think Trent on a bad day is still better than 31 other teams’ left tackles,” Kittle said. “I’m not saying Trent has bad days, but he’s playing at a high level for us -- because we need that.”

Williams said he believes he’s still learning and getting better. He told the NFL on CBS he hopes to play until he’s 40. His improvements are so subtle he can’t describe them.

“It’s consistency, technique, the little things,” Williams said. “It would sound like rocket science if I was trying to explain it to you. We play such a tedious position, and a good game doesn’t mean you had a good outcome. You can play a bad game and have a good outcome.

“You need to be honest with yourself and not look at the scoreboard. Was the effort good enough? Was it better than last week? It’s the only way you can continue to improve.”

Born in Longview, Texas, Williams has taken delight in beating the Cowboys in the playoffs following the 2022 season as well as last year’s regular-season win. He laughed at fans who gave him an obscene gesture when the 49ers won 23-17 at AT&T Stadium and thoroughly enjoyed a 19-12 win over Dallas at Levi’s the following year in the divisional round.

The 49ers blew out Dallas 42-10 last season at Levi’s Stadium in Week 5.

Not that he’s taking anything for granted.

“Obviously we want to get to .500 before the bye week,” Williams said. “We know each other really well. Both of our backs are against the wall. They have as much urgency as we have. We can’t really hang our hat on just saying, ‘Hey, we’ve got to get this one.’ We’ve got to do the things that get you wins instead of talking stuff.”