ST. PETERSBURG, Fla. — The season’s biggest series to date on the line. The reigning American League Cy Young Award winner going for the other guys.

Really, does any doubt exist over whom the Yankees want pitching in this spot?

The starting rotation turned in the Yankees’ favor, and sure enough, so did this Tropicana Field series, with Masahiro Tanaka leading his team to a 7-1 victory over the Rays and Blake Snell that drew the Yankees (24-16) within a half-game, again, of AL East-leading Tampa Bay (24-15).

Don’t let the final score fool you; this was a tight, 3-1 contest through eight innings when, as a testament to the suckiness of this dump of a ballpark, the Trop suffered a power outage. Following an amazing, 43-minute delay, the Yankees turned on their power, adding four runs to put the game out of reach.

The heart of this contest, though, was the pitchers’ duel in which the Yankees and their most reliable big-game starter — the one guy who pitched up to his ceiling in last year’s highly disappointing October — prevailed.

“We’re up against Snell today, who’s absolutely dealing,” Aaron Boone said, “but obviously Masa is able to match him and then some.”

“You try to keep up with him,” Tanaka said, through a translator, of Snell. “He was being efficient, getting outs. And obviously he’s one of the best pitchers in the league right now. Obviously you want to match him. I thought like I was able to do a pretty good job today.”

Obviously, yes, he was, going seven innings and allowing the one run on five hits and no walks, striking out seven. In the early going, as Snell cruised perfectly through the Yankees lineup’s first run, striking out six in a row and seven of nine overall, Tanaka kept pace. This turned into arguably his best start of the season — undoubtedly his most important — because of a healed split-fingered fastball that accounted for three of his strikeouts.

“I definitely think he made strides with his splitter,” catcher Austin Romine said. “That’s the best I’ve seen it in the last couple of outings. … Being able to catch it today, I definitely see there’s more depth with the pitch.”

“I think the splitter, it’s starting to come back,” Tanaka said. “I don’t think it was my best, but I think it was better.”

And when the Yankees broke through with a pair of runs in the fifth, putting together a two-out rally with doubles from Austin Romine and Mike Tauchman and a DJ LeMahieu single, Tanaka recorded a 1-2-3 fifth inning, worked out of trouble in the sixth (after giving up a solo homer to Austin Meadows) and needed only four pitches to get through the seventh, at which point the myriad Yankees fans behind the visiting dugout saluted him with a standing ovation.

“To be honest with you, I didn’t know there was a standing ovation today,” Tanaka said, laughing.

The fans correctly read the situation even though Tanaka threw only 73 pitches. With Meadows due up second in the eighth, Boone justifiably went to Zack Britton, who escaped his own jam before the weirdness of the ninth inning occurred.

There’s nothing weird about Tanaka’s coming through, however. We’re talking about the guy with a career postseason ERA of 1.50. Who gets energized, rather than minimized, by the pressures of his job.

“He tends to always step up for us in big games,” Romine said.

It’s Tanaka’s calling card. You didn’t need the unreliable lights of the Trop to see that he came through again.