He shot for the moon with a pair of three-run homers in Wednesday night’s rout of the White Sox.

But Thursday night, in the finale of this four-game series, Cody Ross reached for the stars, clobbering another three-run homer and lifting the Red Sox to a dramatic 3-1 walkoff victory before a euphoric Fenway Park crowd of 38,413, the largest turnout of the season.

“He loves that situation, he loves being in the big spotlight,’’ manager Bobby Valentine said of his right fielder, who hit out of the No. 5 spot. “He went deep, three runs, we win, and that’s about as much fun as guys have had in a long time. Good feeling.’’

After his contributions in Wednesday’s 10-1 romp, Ross was struck by a sense of déjà vu when he came up with one out in the bottom of the ninth. He drove a 1-and-1 pitch from righthanded reliever Addison Reed into the Green Monster seats to erase a 1-0 deficit.

“It’s an incredible feeling,’’ Ross said after the third walkoff homer of his career and his 16th homer of the season. “It’s something that you can’t really describe with words. The emotions that are going through your body, you’re just trying to take it all in and trying not to rush it and remember it, because you don’t have very many opportunities to do that.’’

The Red Sox were handcuffed by 23-year-old lefthander Jose Quintana, who threw eight scoreless innings, allowing five hits while extricating himself from a bases-loaded jam in the seventh. The Sox started their winning rally against lefthanded reliever Matt Thornton.

Carl Crawford led it off with a single to right. Dustin Pedroia, playing in his first game since coming off the disabled list (strained right thumb), then slapped a grounder to third that wiped out Crawford at second on the force out. Pedroia, however, beat the relay to first.

“We got some timely hits and that’s the stuff guys feed off,’’ Ross said.