DARLINGTON, S.C. — Offering up a fist pump and big smile, Bubba Wallace claimed perhaps the most consequential pole position of his young career — turning in the fastest lap on Saturday in the final round of NASCAR Cup Series qualifying for Sunday’s Cook Out Southern 500 at Darlington (S.C.) Raceway (6 p.m. ET, USA Network, MRN, SiriusXM NASCAR Radio).

Wallace’s lap of 167.143 mph in the No. 23 23XI Racing Toyota puts him out front to start the 500-miler at the historic 1.366-mile Darlington track. And it’s a good beginning for a big night. Wallace currently is just one position below the playoff line — trailing RFK Racing driver Chris Buescher by 21 points entering this last race to set the 16-driver playoff grid.

“Looking at us coming in, being on the bubble, 21 points out, a ton of pressure, well, I think the pressure just switched,” said Wallace, 30, who has four top-10 finishes in his last four races at the track famously nicknamed “Too Tough to Tame.”

“We’re not here to mess around,” he added. “I showed up with a more open and calm demeanor, free and relaxing demeanor, but at the same time, I don’t want to be messed with.

“So it’s a fine balance you have to walk.”

Series rookie Carson Hocevar, 21, will start alongside Wallace on the front row — his best career start in the No. 77 Spire Motorsports Chevrolet. Stewart-Haas Racing’s Chase Briscoe will start his No. 14 Ford third with Hendrick Motorsports’ Kyle Larson and Joe Gibbs Racing’s Martin Truex Jr. rounding out the top five.

Wallace’s 23XI Racing teammate, championship leader Tyler Reddick, will roll off sixth in the No. 45 Toyota. He holds a 17-point advantage over the defending race winner Larson for the regular-season championship that will be decided Sunday night. Larson’s Hendrick teammate Chase Elliott is only 18 points behind Reddick and will start 20th.

Team Penske’s Ryan Blaney – the reigning series champion — Hendrick’s William Byron, JGR’s Christopher Bell and Roush Fenway Keselowski’s Chris Buescher round out the top 10.

After a top-10 showing in practice, Trackhouse Racing’s Ross Chastain will roll off 22nd on the grid. He’s just behind Wallace in the standings, 27 points behind Buescher.

“The first round, I thought we did a good job, the team did a good job of making adjustments for the second round,” said Buescher, driver of the No. 17 RFK Ford. “We were working hard to try to make three and four better because we left a lot on the table there, but then I ended up messing up turn one a little bit. It is still a good start for us.”

Wallace said that he was a little angry at himself after a sixth-place effort in practice, saying he had wanted to “make a statement” and felt he ultimately did so in qualifying.

“Anything can happen,” Wallace said of his playoff potential. “We saw that last week. So we have to run our own race and it makes it a lot easier for us. I have the first pit stall and as long as we execute and make the right calls and do great on pit road. All I want for every single person on this team, including myself, is to go to bed tomorrow night and know we did everything we could, we did all we could. Maybe it was good enough, maybe it wasn’t. That’s the lottery ticket we’ll find out after tomorrow night’s race.”

One of Wallace’s 23XI Racing team owners, four-time Darlington winner Denny Hamlin, said he understands the pressure Wallace is facing trying to race his way into the playoffs in the regular-season finale.

“It’s tough because I think if you’ve got pressure in race 26, then I think that we’ve had 25 other opportunities where the pressure should have been the same,” said Hamlin, who will start 14th on Sunday. “So just what I’ve been preaching is that every race counts.

“You have to bring it every single week. You cannot take one week off in this thing, especially if you aren’t winning. You have to be a top-10 guy every single week. So that’s really, really hard to sustain. I still think Bubba is still on the rise, he’s still getting better, and he’s taken strides over where he was just two years ago. So I’m really happy with the result either way, but I know he’s going to give his 100 percent effort.”