Cubs closer Pedro Strop lost his control, and then Kyle Ryan had a brain cramp on a comebacker.
The Miami Marlins, with the worst record in the majors, found a wild way to win against previously red-hot Chicago.
Strop walked three batters in the ninth inning and Miami took advantage, rallying for three runs to pull out a 6-5 victory Monday night that ended the Cubs' winning streak at seven games.
"Great at-bats all through the ninth inning there," said Neil Walker, who scored Miami's sixth run on Ryan's bad decision. "Scoring three runs in the ninth inning off that guy (Strop) is not easy."
Jon Berti hit his first major league homer, a solo shot off Cole Hamels in the sixth to tie it at 3 after the Cubs had jumped ahead 3-0 against Sandy Alcantara in the first.
Chicago led 4-3 entering the ninth, but Strop (1-2) issued two walks and then yielded a pinch-hit single to Walker as Miami loaded the bases. Strop walked Rosell Herrera to force in the tying run with nobody out. Berti came home from third to put Miami ahead 5-4 when Miguel Rojas grounded out against Ryan.
Martin Prado hit a comebacker to Ryan, who looked back Walker a step toward third after he had come halfway home. But when Ryan threw to first to retire Prado, Walker sprinted across the plate with the third run of the inning.
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"I was on contact," Walker said. "I saw it hit and as soon as it was hit, I'm gone. If he catches it and throws it home, I'd just try to stay in the rundown as long as I can to get the hitter to second.
"I guess he thought maybe there were two outs. I have no idea. It turned out to be a big run."
Ryan acknowledged he just "froze."
"I knew the whole situation," he said. "It could have been a tie game (without the run)."
Cubs manager Joe Maddon had no regrets about calling on Strop, who blew his second save in six chances.
"I feel good about Stropy in that game right there," Maddon said. "His velocity was down. He was just a little off. That's what I saw."
Adam Conley (1-3) pitched a scoreless eighth for the win. Sergio Romo worked around a solo homer by Kris Bryant and single by Anthony Rizzo in the ninth to earn his sixth save.
The Marlins pulled it out despite walking 10 batters themselves.
"That's probably not a very good blueprint in this ballpark with that team," manager Don Mattingly said.
Starlin Castro and Brian Anderson each had an RBI for the last-place Marlins.Rizzo lined a two-run shot in the first for his 200th career homer. Kyle Schwarber and Willson Contreras each had an RBI single.
Rizzo homered for the fifth time in eight games and for the 199th time with the Cubs, moving him past Hank Sauer into ninth place in franchise history.
Hamels allowed three runs and five hits while striking out seven in his third straight no-decision. Alcantara yielded three runs on four hits and six walks in five innings.
In the first, Rizzo lined a sinker against the wind into the right-center bleachers. Javier Baez doubled and Contreras singled him home.
The Marlins trimmed it to 3-2 in the third.
With the game tied at 3 in the sixth, Miami relievers Tyler Kinley and Nick Anderson issued three straight free passes to load the bases with none out. Schwarber followed with a sharp single off Castro's glove at second base to make it 4-3.
EDWARDS RETURNS
Before the game, the Cubs recalled RHP Carl Edwards Jr. from Triple-A Iowa and optioned RHP Dillon Maples to their top farm team. Edwards pitched a perfect seventh.
Edwards started the season with the Cubs, but was sent down April 6 after allowing six runs and five walks in 1 2/3 innings over four outings. While in the minors, the 27-year-old spent seven days on the injured list with a scraped right hand.
Edwards was 8-6 with a 2.81 ERA over the previous two seasons.
TRAINER'S ROOM
Marlins: INF JT Riddle (back) was activated off of the minor league injured list and will report to Triple-A New Orleans. Riddle was demoted in April but remains on the 40-man roster.
Cubs: INF Daniel Descalso (sore left ankle) didn't start for a second straight day, but pinch hit in the ninth. ... C Victor Caratini began a rehab assignment at Class A South Bend. He was 1 for 2, hitting a double as he played for the first time since surgery last month to repair a broken bone in left hand. ... Maddon didn't have an update on LHP Mike Montgomery (mild left lat strain), who was in the clubhouse but had not been activated off the injured list.
UP NEXT
Miami LHP Caleb Smith (3-0, 2.00 ERA) takes the mound against Chicago ace Jon Lester (2-1, 1.73) on Tuesday night. Lester has been his old self in two outings since coming back from a left hamstring strain, yielding one run and five hits while striking out 13 over 12 innings. Smith has won his last three starts, going six innings in each one and allowing only two runs over 18 innings.
