The left-hander hadn't started since Sept. 4 and hadn't won a game since July 27, making him feel miserable while his teammates were fighting for a playoff spot.
But Dusty Baker gave him a start Wednesday in one of the most important games of the season and Estes rewarded his manager's faith with a complete-game shutout in an 8-0 victory over the Reds that enabled the Cubs to retain their one-game lead over Houston in the National League Central race.
Estes (8-11) limited the Reds to four hits in his best outing of the season. The triumph gave the Cubs back-to-back shutouts and reduced their magic number to four.
Estes credited Baker for ignoring the critics and giving him one more chance to prove himself.
"That's one of the major reasons I came here, because I knew Dusty would be in my corner," Estes said. "I know it hasn't always been a popular decision, but hopefully this will do some things and put some people to rest."
The Cubs moved 14 games above .500 (86-72) for the first time this season and will reach the 90-victory mark if they win their final four games.
Carlos Zambrano faces ex-Cub Todd Van Poppel in Thursday's series finaleThursday, hoping to rebound from his season-worst outing last Friday in Pittsburgh.
The offense gave Estes plenty of breathing room early and he dominated from the start. After Kenny Lofton's two-out, RBI single in the second off starter Josh Hall (0-2) ignited the flame, the Cubs added a six-run third.
"I feel fortunate to be in that position," Sosa said. "But on the other side, I have a mission to complete. I know [records] are going to come. I'm young and have a lot of years left in my career. But it's more important to try and win the division."
Estes cruised through the Reds, facing the minimum three batters in six of his nine innings. He retired 11 straight from the fifth through the eighth innings before stranding two in the ninth for his eighth career shutout.
"It makes it a lot easier to feel part of it, absolutely, when you actually get the ball," Estes said.
"I continue to have faith in him because I've seen this before," Baker said. This "was a masterful game, especially with the fact he hasn't pitched very much."
Baker telegraphed his feelings in the earliest days of spring training about having faith in his players.
"My job is to make everyone feel important on the team, which they are, and make them part of the team," he said then. "Like in 'The Art of War.' The small is equal to the big. One is not more important than the other. If it is, then your circle is not complete."
Estes' performance on Wednesday got the Cubs one step closer to closing that circle, with four days remaining to complete the job.