CONCORD, N.C. (AP)—Jimmie Johnson has a commanding lead in the race for the Sprint Cup title. He’s practically on cruise control to a NASCAR-record fourth consecutive championship.

Yet he refuses to claim this title, even after a “perfect weekend” at Lowe’s Motor Speedway gave Johnson his third win in five Chase for the championship races this season. He has a 90-point lead over Hendrick Motorsports teammate Mark Martin at the halfway point of the 10-race Chase.

“I think it’s a nice points lead, but there’s no need for anybody to get too excited yet,” Johnson said. “We’re excited and optimistic, but at the same time, there’s a lot of danger out there. One flat tire, one mechanical (problem), Talladega … I’m not trying to downplay where we’re at, but there’s five races left.

But on a night where most of the championship contenders struggled to stay out of trouble, Johnson was ran another flawless race. He grabbed yet another impressive career milestone Saturday night by closing out a weekend in which he led every practice session and started from the pole with his sixth career victory at Lowe’s.

“This was a personal goal of mine, we’ve been close twice,” said crew chief Chad Knaus, who got the Lowe’s-sponsored No. 48 back to Victory Lane at Charlotte for the first time since 2005.

The win, Johnson’s sixth of the season and 46th overall, moved the Lowe’s-sponsored driver into a tie with Buck Baker for 13th on the career victory list.

More importantly, it extended his lead in the standings to 90 points over teammate Mark Martin at the halfway point in the 10-race Chase.

And in more bad news for the competition? They head next to Martinsville Speedway, where Johnson has won five of the last six races.