Murphy's tiebreaking homer, a call overturned by umpires in yet another review benefiting New York, led an uncharacteristically wild Johan Santana to a 7-4 win over the Washington Nationals on Wednesday night.
Five times this season a disputed home run call has gone to video replay during a Mets game -- four in the past five contests. Two were reversed, and all five rulings ended up favoring New York.
"This game is a weird game," Gary Sheffield said. "They seem to be going our way. I've seen it a couple times and I still couldn't tell."
Murphy had a career-best five RBIs and Sheffield hit an early two-run double off rookie Jordan Zimmermann (2-2), helping the injury-ravaged Mets finish a three-game sweep.
The only lowlight: Top prospect Fernando Martinez, playing his second big league game, failed to run out an infield popup that was dropped. The 20-year-old was booed his next time up.
"I promise that will never happen again," he said. "I'm sorry, to my fans."
Adam Dunn hit a mammoth homer -- estimated at 465 feet, no review needed -- for woeful Washington, which fell 20 games below .500 only 46 games into the season. The Nationals have dropped 15 of 18 since a three-game winning streak.
Santana (7-2) struck out 11 and walked six, one shy of his career high. He labored through six innings, throwing a season-high 120 pitches while allowing three runs and three hits.
"I don't know, something was wrong. It was a crazy night," said Santana, who thought he got squeezed a bit by plate umpire Sam Holbrook. "I've never seen anything like that. The only thing that was good about it was that we won the game."
The left-hander issued four free passes in a 41-pitch fourth, the first time he has walked four in an inning. But the Mets gave him some rare support, with an assist from the video replay system.
Murphy came up with a runner on in the sixth and hit a drive to right that appeared to scrape off a yellow advertisement on the facade of the second deck, which hangs 8 feet over the field.
The ball landed on the warning track and was initially ruled in play, so Dunn started a relay that cut down Sheffield at the plate. Thinking it was a homer, he wasn't running hard most of the way.
"I didn't think that there was any way possible that the ball could have been a homer," Dunn said.
Mets manager Jerry Manuel came out to argue and the umpires huddled before three disappeared under the third-base stands to watch replays. After a delay of about 4 minutes, they returned and signaled home run, giving New York a 5-3 lead.
"I feel like the system worked tonight like it's supposed to work," said crew chief Larry Vanover, the second-base ump. "The light color of the sign and the trajectory of the ball -- and all of a sudden, the ball disappears. It was a very difficult call. It was a consensus of the crew consultation and the replays."
Nationals manager Manny Acta disagreed.
"Something has to be done. This was supposed to help make the right call, to help the umpires," Acta said. "It's supposed to be a clear-cut home run. If it's so inconclusive like the last couple of days, then the call shouldn't be changed like today."
Pedro Feliciano fanned Dunn with a runner on to end the seventh, preserving a two-run lead. It was one of a season-high 15 strikeouts by Mets pitchers.
Murphy, who had an RBI single in the third, added a two-run double in the seventh off Jesus Colome.
Santana remained tied for the NL wins lead with Cincinnati's Bronson Arroyo, who beat Houston 6-1. The two-time Cy Young Award winner reached double digits in strikeouts for the 47th time in his career, four this season.
With 1,652 RBIs, Sheffield tied Hall of Famer Tony Perez for 25th place on the career list. ... New York C Omir Santos was scratched from the lineup with a bruised left shin. He is day to day. ... David Wright struck out four times for the first time in his career. ... Dunn nearly homered off Santana again in the fifth, but his drive was caught by Martinez at the right-field fence. ... Sheffield is hitting .419 with four homers, three doubles and 14 RBIs since May 13. ... The Mets scored 12 runs in Santana's first six starts. They have 21 in his last three outings.