WASHINGTON -- Nationals manager Jim Riggleman had a hunch and it paid off. So did Adam Dunn's video session, which discovered an easily correctible mechanical flaw.
Dunn broke out of a prolonged slump with a homer and five RBIs, sending Washington to a 14-5 victory over the St. Louis Cardinals on Saturday night.
"We needed a win -- bad," said Michael Morse, who had a career-high four hits. "The bats came alive."
Dunn was in an 8-for-66 skid over 20 games when he doubled home two runs for a 4-3 Nationals lead in a four-run third inning. With the score tied at 5 in the fifth, Dunn hit a three-run shot, his 32nd of the season and first since Aug. 11.
"I wouldn't say I'm out of [the slump]," Dunn said. "The last couple of days I've been feeling really good and taking some good swings, trying to figure out why I was missing some pitches. We went back and looked over some tape and it was just a minor mechanical deal."
Dunn was shuffled from cleanup to fifth in Riggleman's new-look batting order, which produced the most runs the Nationals have scored at home since relocating from Montreal to Washington before the 2005 season.
"We were just trying to get some people a little different feel when they went up to the plate," Riggleman said.
Dunn, however, downplayed the effect of the reconfigured lineup.
"I could care less where I hit," he said.
Roger Bernadina, moved to third in the order, homered for the Nationals, who had lost five of six.
Livan Hernandez (9-9) allowed five runs and eight hits in 6 1/3 innings to win for the first time in five starts.
But the Nationals had to overcome two wacky interference calls that went against them and wiped runs off the scoreboard.
"We scored a lot of runs. We fight and fight to try and survive," Hernandez said.
All eight of the runs St. Louis starter Kyle Lohse allowed came with two outs.
"I would get two outs and just couldn't put them away for the third out. I just made a lot of bad pitches when it got to two outs," he said.
The Cardinals took a 3-0 lead in the first. Skip Schumaker singled, moved to second on a groundout and scored on Albert Pujols' ground-rule double down the left-field line. After Matt Holliday popped out, Jon Jay homered to right, his fourth of the season.
Ivan Rodriguez's RBI single got Washington on the board in the second.
The Nationals went ahead 5-3 in the third, and a controversial interference call might have cost them another run.
With Hernandez and Adam Kennedy on via singles, Ian Desmond tried to bunt the runners up. Desmond's sacrifice was a beauty and Lohse threw wildly past first, allowing Hernandez to score. But Desmond was called out by plate umpire Dan Bellino for running inside the baseline and the sacrifice was nullified.
After Bernadina was called out on strikes, Ryan Zimmerman singled a run home, Dunn hit a two-run double and Morse added an RBI single.
RBI doubles by Lohse and Felipe Lopez tied it in the St. Louis fifth.
In the bottom of the inning, Bernadina and Zimmerman singled with two down before Dunn drove a 3-2 fastball from Lohse into the first row of the center-field stands.
"That ball to Dunn," Lohse said, "it just ran right back, inner third. Just stupid things like that cost your team a chance to win."
Lohse (2-6) lasted five innings, yielding eight runs and 11 hits.
Rodriguez had another RBI single in a six-run eighth and pinch-hitter Willie Harris appeared to hit a three-run double only to have Nyjer Morgan called out at home on a weird play. Morgan collided with catcher Bryan Anderson in front of the plate and missed touching home. Third base umpire Angel Hernandez ruled Morgan out because Rodriguez, who had just scored on the play, grabbed Morgan around the waist and pushed him back toward the plate.
Until postgame replays proved otherwise to him, Morgan was convinced he had touched home. Cardinals manager Tony La Russa bristled at the notion that the call was out of the ordinary.
"[Morgan] misses the plate and gets interfered [with] -- where's the crazy call? What's crazy about it?" La Russa said. "No, it's the rule. They screwed up twice and they got nailed for it twice."
Anderson was miffed that Morgan ran into him, calling the play "a cheap shot."
"I turned around and said some things to [Morgan]," Anderson said. "I mean, it's going to take a little bit bigger of a guy to take me down."
Kennedy singled home Harris for a 12-5 lead, and Bernadina later homered to right-center.
Morgan batted eighth for the first time this season. ... St. Louis RHP Ryan Franklin (stiff neck) was unavailable. ... Washington first base coach Dan Radison and LHP Scott Olsen were ejected for arguing the interference call against Desmond. ... Nineteen of the 56 runs Lohse has allowed this season have come in the third inning.