CHICAGO -- Justin Bour continues to be the Miami Marlins' indispensable man.

The Marlins first baseman clubbed his fourth home run in four games -- this one a go-ahead solo shot in the sixth inning -- in a 2-1 victory over the Chicago Cubs on Friday in the opener of a three-game weekend series.

"Three of his home runs have given us a lead and that's huge," Marlins manager Dan Jennings said. "He's taken great swings, the league adjusted to him and he made the adjustment back, and it's fun to watch him in the zone he's in."

Bour, a former Cubs minor leaguer now in his second season with the Marlins, snapped a 1-1 tie with a shot into the right field basket for his 10th home run of the season.

"A homer in any ballpark is cool, but it is very nice that it came (here) in an opportunity to help us win the game," Bour said after the Marlins (35-46) won their fourth straight.

Miami right-handed starter Tom Koehler (7-4) pitched six innings for the win, his fifth in his last six starts dating to May 24 and third consecutive quality start.

"I was happy," Koehler said. "I think my sequencing forced me to throw more pitches than maybe I needed to. But it was a solid team win and we've been playing really good baseball."

Right-hander A.J. Ramos, the fourth Marlins pitcher, allowed one base runner in a scoreless ninth for his 13th save.

Chicago right-hander Jason Hammel (5-4) lost his second straight as the Cubs (42-36) saw a three-game winning streak end.

"Both sides pitched really, really well," Cubs manager Joe Maddon said. "They were able to hit two home runs into 'The Hawk' (east-northeasterly winds) today and bully for them. We had some opportunities and were unable to take advantage of them."

Marlins left fielder Christian Yelich started the scoring with one out in the first inning, sending Hammel's 2-2 pitch to left-center field for his fifth home run of the season.

The Cubs replied and tied it in the bottom of the inning as catcher Miguel Montero's single to right drove in third baseman Kris Bryant, who reached with a two-out double.

Koehler was replaced by right-handed reliever Steve Cishek in the seventh. Koehler gave up one run and five hits, struck out four and walked one.

Hammel departed a half inning later after throwing 97 pitches and allowing two runs and four hits. He struck out five and walked one while giving up two solo home runs.

"It's (unfortunate) the two mistakes you have in the game end up leaving the yard and cost the team a game," Hammel said. "I felt pretty good (but) kind of pitched today without the slider; it wasn't at its best."

NOTES: The final totals won't be announced until Sunday, but Marlins 2B Dee Gordon had a comfortable 1.5 million vote margin over the Cardinals' Kolten Wong for the starting spot in the upcoming All-Star game. Gordon entered Friday with 114 hits, most in the big leagues. ... Gordon is among a contingent of young Marlin batters ages 27 and under who have collectively accounted for 75.7 percent of the team's hits entering July 3. ... The Marlins will send RHP Jarred Cosart (1-3, 4.12 ERA) against Cubs RHP Donn Roach (0-1, 10.80 ERA) in Saturday's middle game. It will be Roach's second Cubs start of the season. ... Chicago OF Jorge Soler was expected to play nine innings for Triple-A Iowa on Friday as he continues a rehab assignment. He went 1-for-3 on Thursday against Round Rock. ... SS Starlin Castro was given Friday off and that allowed the Cubs to move Addison Russell to shortstop and keep 2B Jonathan Herrera in the lineup. On Thursday, Herrera tied a career high with three RBIs, including a two-run homer in the Cubs' 6-1 win over the Mets. ... Fireworks are common at major league games except at Wrigley Field, which hosts a postgame fireworks show for the first time on Saturday night.