Baker homered and matched a career high with four RBIs, Jorge Cantu also connected and the Marlins beat Washington 9-6 on Friday night, dealing the Nationals their seventh consecutive loss and officially eliminating them from postseason contention.
"When your starters don't go more than three innings, it's a roll of the dice," Marlins manager Fredi Gonzalez said. "It's slow-pitch softball style. They've got a pretty good offensive team and we've got a pretty good offensive team. It's not a good feeling. I'm glad we were on the winning end of it, but it could have easily been the other way around."
Cantu and Hanley Ramirez had two RBIs each in Florida's third straight victory.
"It's good when we have  hits and everybody's swinging the bat well at once. That's when we win games," Baker said. "We haven't really ridden any one player besides Hanley for the whole season. When you get multiple hits out of multiple players, it's going to be a good night most of the time."
Badenhop (6-4) allowed one hit over three scoreless innings, part of a stellar effort turned in by the bullpen after starter Sean West was yanked following three ineffective innings.
"He's been like that all season. We've kind of come to expect it from him," Baker said of Badenhop. "It was huge. When the starting pitcher doesn't go deep into the game, you've got to have someone who can and knock out three, four innings for you, and I think he was the player of the game for us today."
The Nationals didn't cash in on the opportunities they had to score once Badenhop entered in the game. Josh Bard stranded eight of the 11 runners the Nationals left on base, leaving the sacks full in the fourth against Badenhop and in the seventh against Kiko Calero.
"We had a lot of chances. ... We just could not get the big hit," Nationals interim manager Jim Riggleman said. "It was a combination of they made their pitches at the right time and the bullpen threw six innings of one-run ball."
Leo Nunez pitched the ninth for his 18th save in 23 tries.
Josh Willingham homered for the Nationals, who equaled their season's longest losing streak.
Florida took a quick 3-0 lead in the first against Garrett Mock, starting in place of Craig Stammen, who was scratched with a sore right elbow. After the game, general manager Mike Rizzo said Stammen would undergo season-ending surgery Sunday to remove a bone spur from his right elbow.
Chris Coghlan extended his hitting streak to 12 games with a leadoff single and moved to second on a groundout before scoring on Ramirez's single to left. Cantu followed with his 14th homer, a shot to left off an 0-2 pitch.
Washington got within 4-2 in the second on Gonzalez's two-run triple.
Baker's two-run homer made it 6-2 in the third. Cantu drew a leadoff walk before Baker lined a pitch into the first row of the left-field stands for his career-high ninth homer and third this season against Washington.
Ryan Zimmerman tripled with two out in the bottom of the inning, then scored on Dunn's bad-hop single past first. Willingham hit West's next pitch over the wall in left for a two-run homer, making it 6-5.
Both starting pitchers departed after three innings. West gave up five runs on seven hits and struck out four. Mock (3-7) allowed six runs on seven hits.
"I wasn't throwing the ball," Mock said. "It's grenade launching."
Baker singled home Ramirez, who had led off the fifth with a double, for a two-run lead. Ramirez's sacrifice fly and Baker's RBI single made it 9-5 in the sixth.
Zimmerman drove in a run with an infield single in the eighth.
The outing was West's shortest in 17 career starts. ... The Nationals added left-hander Victor Garate to the roster before Friday's game. Garate was claimed off waivers from the Los Angeles Dodgers to complete an Aug. 30 trade for infielder Ronnie Belliard. Washington also activated catcher Jesus Flores from the 15-day disabled list, but he is still strengthening a right shoulder injury and will initially be limited to pinch-hitting duties.