Daniel Murphy celebrates with Ben Revere and Danny Espinosa after the Nationals’ 9-1 win Thursday. Revere and Espinosa each had a pair of hits and Murphy hit a home run. (Frank Franklin II/Associated Press)

Just as Mets Manager Terry Collins reached the Citi Field mound, Matt Harvey began walking off it. The Washington Nationals are accustomed to a different version of Harvey, the Mets’ Opening Day starter and presumptive ace. But that Harvey has gone missing, a disappearance the Nationals hastened by spraying his pitches all over the field in a 9-1 demolition Thursday to take two of three from New York.

The Nationals overpowered Harvey, chasing him after just 2⅔ innings that included eight hits and nine runs (six earned), the worst start of his career. Daniel Murphy continued his torrid hitting, smashing a two-run home run off Harvey in the first. In the third, the Nationals’ lineup batted around and hung seven more runs on Harvey, who trudged straight to the Mets clubhouse to a chorus of boos.

“That’s tough,” Nationals right fielder Bryce Harper said. “He’s got a great arm and he’s a lot of fun to watch. I’ve always said that. He’s one of the best in baseball.”

Harvey’s struggles proved to be the cure for scuffling Ben Revere (two hits, two RBI) and Anthony Rendon (three hits, two RBI).

“We saw the ball up, saw his heater and put them in play,” Revere said.

Stephen Strasburg tossed six strong innings, striking out 10, walking one and allowing one run to improve to 7-0. Dating back to last season, the Nationals have won Strasburg’s past 13 starts, a team record.

Harvey’s woes started early. In Murphy’s first at-bat against his former teammate, the second baseman fouled off two hard fastballs after being down 0-1. He then stayed back on a curveball over the plate and sent it to dead center for a two-run shot, the Nationals’ first homer on an 0-2 pitch this season.

“A big series for us,” Murphy said. “It’s nice to go on the road in the division and get two out of three.”

Murphy added a double and an intentional walk in the third inning. He finished 2 for 4 and is batting a major league-best .397.

“He’s a stud,” Harper said of Murphy. “It’s a lot of fun to have a guy on your team that’s doing what he’s doing.”

After Strasburg gave up his only run in the second inning, the Nationals roared back in the third. Revere smacked a single to start the rally and later drilled a triple to chase Harvey. In between, Harper, Rendon, Wilson Ramos and Danny Espinosa all notched hits — none of which were cheap.

Washington Nationals pitchers Max Scherzer has nearly 60 dives under his belt and has traveled to Fiji, Mexico and the Caymans. (Max Scherzer)

“I lost my rhythm,” said Revere, who returned two weeks ago from an oblique strain. “I took a month off. Just keep battling and you get your rhythm back. Today it felt really good.”

Adding to Harvey’s woes was his defense — former Nat Asdrubal Cabrera booted Ryan Zimmerman’s groundball, leading to a run. Harvey also cut off Michael Conforto’s throw home after Ramos’s two-run single that might have forced a close play on Rendon, who scored.

The Nationals sent 11 batters to the plate in the inning. Harper’s hit snapped an 0-for-21 career mark against Harvey, which had tied the record for longest active hitless streak between a pitcher and a hitter.

“I’ll take any record I can in the book,” Harper said.

Perhaps Harvey’s large workload last season, his first back from Tommy John surgery, has taken a toll on him. But Strasburg, whom the Nationals handled with care following his 2010 Tommy John surgery, was strong. Manager Dusty Baker hoped Strasburg would get through seven innings but he provided just six because of a high pitch count. Since he returned from a back issue last summer he has a 2.20 ERA over 22 starts.

The Nationals’ lead was so comfortable by the seventh inning that Baker let Strasburg hit for himself in the top of frame even though he was done pitching. Baker didn’t want to waste a bench player for a pinch hit appearance because he planned to swap in four reserves — Stephen Drew, Clint Robinson, Michael A. Taylor and Chris Heisey — to give regulars rest.

The Nationals left New York late Thursday, bound for a three-game series in Miami with newfound confidence they can beat tough teams without major contributions from Harper. The National League MVP went just 1 for 9 at Citi Field with four walks, yet the Nationals won the series and outscored the Mets in the process, 16-4.

“I hope we do the same thing in Miami,” Baker said. “We’ve just started this road trip and we’ve got to keep it rolling. We’ve got some guys that are starting to swing the bat pretty good in this series.”