NEW YORK -- Amid a team-wide power outage and despite some organizational reservations, the Mets on Wednesday relented to make a move they have resisted for several weeks. The team called up corner infielder Mark Vientos and started him at third base against the Rays, in hopes that he could provide a power spark for their flagging lineup. 

Immediately, Vientos did exactly that, hitting a game-tying, two-run homer in the team’s 8-7, walk-off win over the Rays at Citi Field.

“It was good for sure that all the hard work I’ve been putting in is showing,” Vientos said. “It just tells me that I need to continue what I’ve been doing and keep working and keep learning. Whatever I can do to help this team win is why I’m here.”

The club’s seventh-ranked prospect according to MLB Pipeline, Vientos had hit his 13th home run in 38 games Tuesday night for Triple-A Syracuse, improving his slash line to .333/.416/.688 at that level. He briefly made his Major League debut late last summer, batting .167 with a homer in 16 games. One of the youngest members of his 2017 Draft class, the former second-round pick has hit 90 career homers since turning pro.

If Vientos can come anywhere close to his peak production with the Mets, he could do wonders for an offense that recently snapped a streak of 56 consecutive innings without a homer.

Still, general manager Billy Eppler said, “This wasn’t born out of necessity. Mark earned his way up here. He pushed his way onto this roster, and we want to give him every opportunity here.”

As if to prove it, Vientos crushed a Ryan Thompson slider 414 feet to straightaway center field in the seventh inning of his return to the Majors, paving the way for later dramatics from Francisco Álvarez and Pete Alonso.

“These guys work hard to get a chance up here,” manager Buck Showalter said. “Your reward for doing it well is a chance to do it again tomorrow.”

Whether that means everyday chances in the starting lineup remains to be seen. Although Vientos has improved defensively over the past year, the Mets have Brett Baty and Alonso entrenched at the corner infield positions. Vientos, a right-handed hitter, could find it difficult to draw DH reps over lefty Daniel Vogelbach, even though Vogelbach has just two home runs and a .369 slugging percentage this season. The Mets also acquired Tommy Pham just four months ago to serve as the right-handed half of that platoon.

Asked about the opportunity for Vientos to play against right-handed pitchers, which he has dominated in the Minors, both Showalter and Eppler demurred.

“He’s going to play tonight, we’re going to see how it evolves,” Showalter said before Wednesday’s game. “That’s a good question -- one that I’ve asked myself, obviously. I just don’t think going there in stone right now is real smart.”

Perhaps the Mets are finally ready to make that sort of move, given the inconsistencies of their offense. The call for Vientos follows similar promotions of Baty and Álvarez, the organization’s top two prospects entering this season. A fourth blue-chip prospect, shortstop Ronny Mauricio, remains at Syracuse, where he is batting .354/.390/.615 over 40 games. Mauricio, at least, can spend his time at Triple-A continuing to learn other defensive positions, whereas Vientos had essentially nothing left to learn at the level.

The last frontier for Vientos to conquer was his strikeout rate, which fell from 30.8 percent through April 16 to 15.8 percent since that time. Vientos has also demonstrated defensive improvements and says he feels equally comfortable at both corner infield positions.

“I don’t have that much experience, but I feel like I’m in a better spot,” Vientos said, comparing his callup to his Major League debut last September. “I feel like I’m a lot better than I was last year. So I’m confident with that.”

Upon hitting his final Minor League homer on Tuesday, Vientos returned to his hotel room and was about to go to sleep when Syracuse manager Dick Scott called him with news of the promotion, which resulted in infielder Luis Guillorme being optioned to Syracuse. Vientos slept a bit more fitfully than he otherwise would have, before waking up early to board a flight to Queens.

“I’m just going to come out here and do my thing,” Vientos said. “I’ll just come out here and play my game and see what happens.”