"It was a great performance," Nationals manager Davey Johnson said. "He was throwing everything over -- change, curve, fastball. It was fun to watch."

Gonzalez held the overmatched Mets hitless into the seventh before pinch hitter Zach Lutz broke up the bid with a soft single. Lutz swung at the first pitch of the inning and sliced a looper that landed on the first base line, taking out a chunk of chalk well behind the bag for New York's lone hit.

"Off the end of the bat," Lutz said. "It was good luck."

First baseman Adam LaRoche made a diving attempt as the ball hit the dirt, but it squirted by and into foul territory along the right field line. First base umpire John Hirschbeck correctly called it fair, and Gonzalez (10-6) paused behind the mound to stare in that direction.

"LaRoche came over to me and said, 'I'm sick to my stomach.' All the guys came over and said the same thing," said Gonzalez, who won 21 games last season and finished third in NL Cy Young Award voting.

After the hit, Gonzalez kept sailing along in a dominant outing. He struck out eight and walked two for his second career shutout and fourth complete game, improving to 5-0 in six starts against the Mets since last year's All-Star break.

Denard Span and Ryan Zimmerman hit back-to-back homers to start the game. Jayson Werth and Tyler Moore also connected off Carlos Torres (3-4), roughed up by Washington for the second time in six weeks.

Wilson Ramos added a three-run shot off reliever Greg Burke.

The five home runs were the most a team has hit in one game at Citi Field, which opened in 2009.

Handed a huge lead, Gonzalez was in cruise control as he won his third straight start. He faced three batters more than the minimum to help the Nationals, on the fringe of the NL wild-card chase, win their third in a row and fifth in six games.

The only ball the Mets hit hard was a line drive to shortstop by Juan Lagares in the fifth. Gonzalez walked his second batter and penultimate one.

"Fortunately, we put a ball in play where no one was at so we go home at least knowing we didn't get no-hit," Mets manager Terry Collins said. "Obviously, we feel very fortunate."

Washington gave Gonzalez a two-run lead before he took the mound, hitting two homers on Torres' first eight pitches.

Span's shot to right field was his sixth career leadoff homer and first for the Nationals this season. It also extended his hitting streak to 20 games, the longest active run in the majors.

Zimmerman followed with a drive to left-center for his fourth home run in three days and sixth in the last seven games.

It marked the third time this season that a team hit back-to-back homers to begin a game, according to STATS. Matt Carpenter and Carlos Beltran did it for St. Louis on April 26 against Pittsburgh, and Kole Calhoun and Mike Trout connected for the Los Angeles Angels on Aug. 6 against Texas.

Steve Lombardozzi and Bryce Harper were the last Nationals pair to achieve the feat on June 3, 2012, against Atlanta. The previous time the Mets served up homers to the first two batters in a game was June 28, 2003, when Alfonso Soriano and Derek Jeter went deep for the Yankees, STATS said.

"That was the first time I had ever seen it," Mets catcher Travis d'Arnaud said.

Span singled in the third, Zimmerman walked and Werth hit a three-run shot to left-center.

Moore opened the fourth with a long drive to straightaway center, making it 6-0. Ramos connected in the fifth, and the only drama left was Gonzalez's pursuit of a no-hitter.

Torres gave up six runs and five hits in four innings. He's made four solid starts for the Mets and turned in two duds against the Nationals, including their 14-1 rout on July 28.

Game notes
Collins confirmed that injured closer Bobby Parnell will have season-ending surgery to repair a herniated disk in his neck. The team hopes Parnell will be ready for spring training. ... Harper sat out again with a sore left hip. Scratched from the lineup Saturday in Miami, Harper was examined by team doctors in Washington, and Johnson said tests showed inflammation but no structural damage. The 20-year-old slugger will take oral medication and miss at least the first two games of the series. ... Johnson said RHP Tanner Roark will start the series finale Thursday. ... Span had three hits. ... Gonzalez's other shutout was a five-hitter against St. Louis on Aug. 31 last year. ... The 70-year-old Johnson has said this will be his final season as a major league manager, so this series marks his last scheduled visit to Queens, where he piloted the Mets to the 1986 World Series title at old Shea Stadium. He said it's always fun to come back, but he feels "too young to retire" and wouldn't be averse to some sort of challenging baseball job in the future.