However, the veteran left-hander pitched his team to the brink of a second straight National League Central title on Monday night, with plenty of help from the offense.
Should the Cubs win Tuesday night or the Milwaukee Brewers fall at home to the Cincinnati Reds, then Chicago would pop the champagne in its archrival's ballpark. And if Lester's performance in this game was any indication, the Cubs might feel better about his chances to make his usual sizable postseason contribution.
Lester (12-8) gave up a run and five hits, walking two and fanning four. While he threw just 58 of 103 pitches for strikes, Lester exhibited crisper stuff and better command as the evening progressed, retiring eight of the last nine batters he faced.
"I felt better," Lester said. "My command could have been a bit better early, but I was a little sharper today than I have been. It was good tonight. Overall, it was definitely a positive step."
The only run Lester yielded came when Jedd Gyorko belted a 410-foot homer in the second inning, a blast that landed in the third deck in left field. Then again, Chicago already led 5-0 by that point, and it was 8-1 for the last four innings of Lester's outing.
Simply put, the Cubs (88-68) resembled last year's deep offense in dismantling rookie right-hander Luke Weaver (7-2), who came into the game with seven consecutive wins.
Weaver entered the night having allowed eight runs in his past seven games. Chicago needed just three innings to match that total, as the Cubs took advantage of a spate of pitches over the plate's heart for crushing two-out hits.
Addison Russell ripped a three-run double down the right field line in the first, followed by Jason Heyward's RBI double to right-center. Kris Bryant drilled a solo homer in the second, and Javier Baez cracked a three-run shot to left-center an inning later that essentially ended the game's competitive phase.
Weaver was lit up for eight runs on seven hits and two walks in three innings. He fanned three.
"He got into some tough counts and had to hit more of the plate," St. Louis manager Mike Matheny said of Weaver. "It's a tough game, and it was a good lineup he was facing."
Cubs manager Joe Maddon sensed Weaver was off his game after Bryant laced a one-out single in the first.
"Looking at it from the side, that seemed to knock him off track," Maddon said. "You look at his numbers the last seven starts -- lot of strikeouts, almost no walks -- and he's been a really good pitcher. Give our guys credit for playing that kind of game tonight almost from the first pitch."
Pinch hitter Tommy La Stella and Jon Jay finished Chicago's scoring with RBI singles in the eighth. All 10 Cubs runs came with two outs.
Adding injury to insult for St. Louis (81-75), All-Star catcher Yadier Molina left the game in the seventh after taking consecutive foul balls off the mask. Molina was placed in the concussion protocol, and the team is hopeful he will be able to play on Tuesday.
The Cardinals were eliminated from the division race with their third straight loss. They trail the Colorado Rockies by 2 1/2 games for the NL's second wild card.
Meanwhile, Chicago is a game away from earning a chance to defend its World Series title. And the outing from Lester, who still carries a 4.46 ERA, gives the Cubs more reason for October optimism.
"I just have to get back to being me," Lester said. "I have to put hitters on the defensive as opposed to pitching from the scouting report from pitch one."
NOTES: Jose Quintana's shutout Sunday at Milwaukee was the Cubs' first by a lefty since Rich Hill had one on Sept. 16, 2006, in a 4-0 victory over Cincinnati. ... St. Louis 1B Jose Martinez (thumb) wasn't in the starting lineup for a third consecutive game, and there is no timetable for his return. Martinez will take some swings before the Tuesday night game with hopes of getting back into games in the final week. ... If the Cubs can clinch a playoff spot, it would mark their third straight postseason berth, the first time they would have done so since 1906-08.