CLEVELAND — The party started early and for a while appeared as if it might last all night.

Here were the Mets launching shots all over the ballpark and finally resembling a respectable lineup. It could have been manager Terry Collins’ tweak to the batting order, but more likely the Mets were just due.

When it was finished, the Mets had hit four home runs — double the total they had entering the game — leading to a 6-5 victory over the Indians at Progressive Field.

“That’s what got us where we did last year was power, and power is something we have to have,” Collins said.

Michael Conforto, Alejandro De Aza, Yoenis Cespedes and Neil Walker all went deep for the Mets and Bartolo Colon kept his team competitive. But it got scary for the Mets in the ninth, when Carlos Santana hit a two-run homer against Addison Reed and Jeurys Familia struggled to get the last out, before retiring Jose Ramirez with the tying run at second base.

In a return to where his major league career started in 1997, Colon lasted 5 ¹/₃ innings and allowed two runs on eight hits with one walk and five strikeouts.

It was a second straight solid start for Colon, who allowed one run over six innings against the Phillies last Saturday but took the loss.

With the victory, Colon tied Pedro Martinez for second all-time in victories (219) by a Dominican-born pitcher. Juan Marichal holds the record with 243.

After watching the Mets average just 1.6 runs over the final five games of their 2-4 homestand, Collins moved Conforto from sixth to third in the batting order, hoping it would provide a jump start.

Conforto finished 2-for-5 and will remain third in the order.

“It’s where I’ve always hit in the past,” Conforto said. “Obviously it’s a little different here, but it’s a spot I want to earn, so there’s things I’ve to do to earn it and I think today was a step in the right direction.”

Collins cited Conforto’s on-base percentage for the move and said he’s not worried about putting too much pressure on the second-year outfielder.

“I saw what he did in the World Series, and that spoke volumes, that he certainly can handle the situation of hitting third,” Collins said. “We decided to give it a shot.”

The Mets hit three homers during a fifth inning in which they sent nine batters to the plate and took a 6-1 lead. Walker’s two-run blast batting right-handed — his weaker side — culminated the five-run outburst in the inning.

“A lot of things I was working on in spring training have come to fruition for me,” Walker said, noting his timing has improved batting right-handed.

The three-homer inning was the Mets’ first on the road since July 16, 2006, at Wrigley Field, where Cliff Floyd, Carlos Beltran and David Wright all homered.

De Aza homered leading off the fifth and, with two outs, Cespedes followed Conforto’s infield single with a blast that cleared the fence in right-center.

“I don’t think we put an emphasis on [homers], but that is kind of how this lineup is constituted,” Walker said.

Conforto launched a solo homer with two outs in the first against Cody Anderson to get the Mets a fast run.

Mike Napoli’s RBI single in the first tied it 1-1 after Jason Kipnis had doubled with one out. Colon allowed two singles in the second, but then retired nine of the next 10 batters he faced.

Antonio Bastardo, Hansel Robles, Reed and Familia combined to pitch the final 3 ²/₃ innings, keeping active a bullpen that had been pushed to the limit on the Mets’ recent homestand.

The best sign might have been 1 ¹/₃ scoreless innings from the lefty Bastardo, who struggled in his appearance against the Marlins on Monday.