CHICAGO -- Joe Maddon arrived to the postgame press conference drenched from the victory celebration Sunday night. Liquid dripped from his hat, and the Chicago Cubs manager used a towel to dry his glasses.

The come-from-behind, extra-inning win was another memorable one for the Cubs, who own the best record in baseball.

Chicago rallied from an early six-run deficit, tied the game with three runs in the ninth and won it on pitcher Jon Lester's bunt in the 12th during a 7-6 victory over the Seattle Mariners on Sunday night.

Lester, a pitcher with an .051 career batting average entering Sunday, bunted on a 2-2 count with a runner at third base and one out. He perfectly placed the ball near the first base line, allowing Jason Heyward to score.

"I wasn't thinking at all. There was no thinking involved for me," Lester said. "I was trying to pay attention and not miss any signs. I was trying not to screw anything up. That's really it. As long as I got it down and see what happens after that."

Lester, who never previously appeared as a pinch hitter in his 11-year major league career, collected his fifth career RBI.

"He did a good job of getting it down," said losing pitcher Cody Martin (1-1). "He completely deadened it. I had a longer run than you'd want to get to the ball. If he hits it any harder, most likely I make that play. Kudos to him."

Added Maddon: "Jon's a really good bunter."

Robinson Cano, Nelson Cruz and Dae-Ho Lee homered in the first three innings for the Mariners, who have lost 12 of 21.

The National League Central-leading Cubs (63-41) took two of three games against Seattle (52-51).

Heyward doubled to lead off the 12th. He advanced on Willson Contreras' sacrifice fly before coming home on Lester's bunt, sliding under the tag of catcher Mike Zunino after Martin flipped the ball to the plate with his glove.

The Cubs tied the game in the ninth against Steve Cishek, who blew a save for the sixth time in 31 chances. Addison Russell's RBI single made it 6-4 before Heyward was hit by a pitch to load the bases. Another run scored when the Mariners were unable to complete a double play on Contreras' grounder. The tying run scored on a wild pitch.

"Stuff was terrible tonight," Cishek said. "I had a hard time commanding my fastball, slider was the not the same, and I got exposed."

Hector Rondon (2-2) pitched two perfect innings for the win.

"Give them credit, they didn't quit," Mariners manager Scott Servais said. "They kept battling back, and they've done that probably a few times this year. It's disappointing. I thought we had the game in hand."

In five innings, Seattle starter Felix Hernandez allowed two runs and two hits -- the fewest he has given up in three starts since returning from the disabled list July 20 after recovering from a strained right calf. He also struck out eight but walked five. He had surrendered nine runs and 19 hits in 12 2/3 innings in his two previous starts since coming off the DL.

Seattle had a chance to blow open the game, loading the bases with no outs in the sixth. Joe Nathan exited after allowing a walk and a double. After another walk, Travis Wood got two strikeouts and a popout to prevent any scoring.

The Cubs pulled to within three on Ben Zobrist's triple in the seventh.

Among the Cubs' defensive highlights, Wood moved from the mound to left field in the seventh and crashed into the ivy catching a potential Franklin Gutierrez extra-base hit.

"It doesn't surprise me with him," Maddon said. "This guy's a really good athlete. The surprise was against that wall. I thought it was a home run the moment it was hit."

Wood returned to the mound and recorded the last out of the eighth.

"This was an exciting one with everything going on," Wood said.

Spot starter Brian Matusz struggled from the get-go in his Cubs debut. Cruz hit a two-run homer -- his 26th home run of the season -- for a 2-0 Mariners lead in the first. Seattle then loaded the bases on a hit batter and two walks before Matusz got Zunino to fly out to end the inning.

Cano also hit a two-run homer -- his 23rd long ball of the season --in the second.

The Mariners added a third two-run drive in the third from Lee, his 13th homer of the year.

Matusz gave up six runs and six hits in three innings.

"He had a tough night," Maddon said. "He threw some nice pitches, but obviously they got to him pretty firmly."

Maddon said before the game he would be satisfied if Matusz pitched five innings. Chicago started him because he could have opted out of his contract if the Cubs hadn't promoted him -- and the move gave their other starters rest. Matusz allowed eight runs in six relief innings for the Baltimore Orioles before they traded him May 23 to the Atlanta Braves, who released him June 3.

Carl Edwards Jr. replaced Matusz and struck out five of the six batters he faced.

"They've got the best record in baseball, and quite frankly, we should have got two out of three," Servais said. "It didn't happen. You've got to finish."

NOTES: The Mariners announced that LHP Wade Miley (7-8, 4.98 ERA) was traded to the Orioles for LHP Ariel Miranda, one day after Miley held the Cubs to one hit and one run in seven innings. ... The Mariners' rotation for their series against Boston at Safeco Field is expected to be LHP James Paxton on Monday, LHP Wade LeBlanc on Tuesday and RHP Hisashi Iwakuma on Wednesday. Miley was scheduled to start Thursday. ... The Cubs optioned RHP Justin Grimm to Triple-A Iowa after Saturday's game to make room for Sunday's starting pitcher, LHP Brian Matusz, whose contract was selected. Grimm has a 4.72 ERA in 45 relief appearances. He took the news well and will eventually return to the team, Cubs manager Joe Maddon said. ... Maddon said he was unaware that closer Aroldis Chapman dislikes four-out save opportunities. Chapman got four outs for a save Thursday against the Chicago White Sox before he blew a save Saturday against the Mariners when he was also called upon with two outs in the eighth. Chapman told reporters four-out saves are not his "favorite thing."