"Dan Haren set the tone again," Jennings said. "Win No. 6. He did a good job grinding through what he did and set the tone early. It's a good to see us hang that big crooked number up [four runs in second]."
Stanton and Baker belted back-to-back home runs off Lester in the fifth inning, giving Miami a six-run lead.
But in the sixth, Haren walked Anthony Rizzo with one out and Junior Lake blasted a two-run homer. As Lake was rounding third, he signaled toward the Miami dugout to quiet down. Benches cleared after Lake touched home. In the fourth inning, Haren hit Starlin Castro with a pitch. Castro homered on Monday and took his time admiring the shot.
Miami took a four-run lead in the second inning. After Lester retired the side in order in the first, the Marlins got on the board when J.T. Realmuto laced an RBI double to left. Adeiny Hechavarria picked up a run-scoring infield single. A pivotal play came when Miami challenged Dee Gordon's groundout to short, which would have been the third out. The call was overturned, and instead of settling for two runs, the Marlins scored twice more.
"We needed that," Gordon said. "I just had to hustle. I thought I was safe."
"They did a good job of getting the momentum on their side in that [second] inning and scrapping some hits," Lester said. "I didn't do a good job of making that momentum go away and back to our side."
Jennings was ejected in the eighth inning, disputing a ball-four call on Cubs catcher David Ross, who was awarded first base after an appeal.
MOMENTS THAT MATTERED Realmuto's full-count double: Realmuto, Miami's rookie catcher, worked an impressive at-bat off the Cubs' savvy veteran in the second. Lester was ahead in the count, 1-2, but Realmuto worked the count full before lining the seventh pitch of the at-bat for an RBI double, opening the scoring in Miami's four-run inning.
Szczur chases Haren: Matt Szczur's pinch-hit RBI single in the top of the sixth knocked Haren from the game and cut the Marlins' lead to 6-3. Szczur's hit followed the benches-clearing incident.
Stanton/Baker back-to-back: The Marlins hadn't gone back-to-back all season until Saturday night at Citi Field. In that game, Stanton and Baker did it. Four days later, the two combined once again. In the fifth inning off Lester, Stanton and Baker hit successive homers that padded Miami's lead to six runs.
Lester scuffles: Coming off a 10-strikeout performance in his last start, Lester wasn't nearly as sharp on Wednesday. He allowed six hits in Miami's four-run second inning before surrendering two fifth-inning home runs. In all, the lefty was roughed up for a season-high-tying six earned runs on nine hits in five innings.
With two outs in the bottom of the second inning, Gordon hit a grounder to short and Castro threw to first. Initially, Gordon was ruled out. Miami challenged the call and it was overturned in 59 seconds, as the replay showed Gordon beat the throw to first. In turn, Realmuto scored on the play for the Marlins' third run of the inning. Miami then tacked on another run in the inning for a 4-0 lead.
"It feels good. But we've got to win a lot more series to get back to where we want to. The goal is to get somewhere around .500 by around the All-Star break or a little bit after and go from there. I know we have a couple pitchers coming back. ... Hopefully we can climb into it a little bit and cut the deficit down. You win a couple series and everybody feels good about it." -- Haren, on winning two straight series
"I don't want us to take a page out of 'Major League' and flamboyantly flip a bat after a long home run. I don't want that at all. That has nothing to do with us ascending. I would even like to use this moment even for our Minor League guys that it doesn't play. For our kids watching, it doesn't play. Don't do that; that's not cool. It's very, very much not cool. If you're watching the game back home in Chicago tonight, don't do that."-- Maddon, on Lake's reaction following his homer
SOUND SMART WITH YOUR FRIENDS
By going 0-for-1 on Wednesday, Lester fell to 0-for-25 on the season and 0-for-61 for his career. He threatened to break his hitless streak with a hard line drive to center field, but Marcell Ozuna was able to track it down.
WHAT'S NEXT Cubs: The Cubs head to Washington to open a four-game set with the Nationals on Thursday at 6:05 p.m. CT at Nationals Park. Jake Arrieta, who's 4-4 with a 3.18 ERA on the season, gets the start for Chicago.
Marlins: Off on Thursday, the Marlins open a three-game series vs. the Rockies on Friday at Coors Field at 8:40 p.m. ET. Tom Koehler (3-3, 4.01 ERA) gets the start for Miami, with Colorado countering with Eddie Butler (3-5, 4.22).
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter @JoeFrisaro and listen to his podcast. Steve Wilaj is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.