CINCINNATI -- After a string of close games, the Cincinnati Reds were glad to get a breather.
Miller's three-run shot and Joey Votto's two-run homer created a cushion for Wells, who put together his longest outing since being acquired by the Reds as a free agent on July 7 and joining the team July 31.
Cincinnati manager Dusty Baker was thankful for a blowout win after watching his team play five consecutive one-run games and eight in a row decided by no more than three runs. The Reds had played 17 straight games that were decided by four runs or less since beating Pittsburgh 11-5 on Sept. 1.
"That was great," Baker said. "A lot of crooked numbers. Corky Miller had a big day. Kip Wells threw the ball well. He minimized his pitches. Not walking anybody was the key. He didn't have a lot of strikeouts, but he got a lot of ground balls and balls not hit very hard."
The Marlins began the day trailing Colorado by four games for the NL wild card. They were seven behind first-place Philadelphia in the NL East.
Wells (2-4), who opened the season in Washington's minor league system and went 0-2 for the Nationals before being released July 6, pitched seven-plus innings. Using his off-speed pitches to set up his fastball, he gave up one run and five hits with no walks and two strikeouts. His previous longest outing with Cincinnati was 6 2/3 innings against Houston in his last start Tuesday, when he did not receive a decision.
"I've been throwing my changeup more in the past month," Wells said. "I was falling behind early, but I was always able to eventually get it over the plate and get them to whack it at somebody."
Wells faced the minimum 11 batters through the first 3 2/3 innings before NL batting leader Hanley Ramirez singled to center field for Florida's first hit.
"Wells' sinker was working good for him today," said Florida's Dan Uggla, who was 0 for 3 against the Cincinnati starter. "I don't know about everybody else, but I swung at a lot of bad pitches."
Darnell McDonald led off the third for Cincinnati with an infield single to shortstop. One out later, Wells sacrificed McDonald to second and he scored on Drew Stubbs' double into the left-field corner.
Florida starter Sean West walked Scott Rolen and Jonny Gomes with one out in the fourth. McDonald struck out, but Miller smacked West's first pitch into the left-field seats for his first home run in the majors since June 11, 2008, for Atlanta against the Cubs at Chicago.
Miller, who has played at least one game in the major leagues in every season since 2001, hit his first homer for the Reds since June 22, 2002, at Atlanta. He doubled his RBI total for the season.
"You never know when it's going to be your last one," Miller said. "It was great to get a four-run lead and give Kip some breathing room. That helped a lot."
Stubbs led off the fifth with an infield single and Paul Janish followed with a bunt single. Votto struck out looking, and Florida manager Fredi Gonzalez called in right-hander Cristhian Martinez to face Brandon Phillips, who hit the first pitch through the hole into right field for an RBI single to give Cincinnati a 5-0 lead.
"I got backed into a corner today and couldn't fight my way out of it," West said. "I didn't have my good stuff today. It's a huge learning experience coming from Double-A. I let my team down today. I think they expected more from me."
Votto hit his 22nd homer in the seventh, a two-run shot, and Scott Rolen later followed Phillips' triple with a run-scoring groundout.
West (7-6), who had gone 4-1 with a 4.15 ERA in eight starts since being recalled from Double-A Jacksonville on Aug. 8, gave up five hits and five runs with three walks and four strikeouts in 4 2/3 innings.
"It's the stuff you have to deal with in a young pitcher," Gonzalez said. "He takes a couple of steps forward, then one back."
Votto hit 21 home runs in his first full season last year. ... The Reds went 9-8 in their most grueling stretch of the season -- 17 games in 17 days. Monday is their first day off since Sept. 3. ... Florida hasn't won a series in Cincinnati since taking two of three Aug. 5-7, 2005. ... Cincinnati RHP Johnny Cueto threw a bullpen and was pronounced ready to start Tuesday at Pittsburgh. Cueto missed his last scheduled start on Thursday with flulike symptoms. RHP Justin Lehr and LHP Matt Maloney will start the Reds' first two games next weekend in Houston.