ST. LOUIS >> Jonny Gomes got the Red Sox even in this wild World Series, thanks partly to Shane Victorino’s aching back.

Inserted into the lineup about 75 minutes before gametime, Gomes hit a three-run homer off reliever Seth Maness in the sixth inning that led Boston to a 4-2 win over the St. Louis Cardinals on Sunday night, tying the World Series at two games apiece.

Felix Doubront and surprise reliever John Lackey, both starters during the regular season, picked up for a gritty Clay Buchholz to help the Red Sox ensure the Series will return to Boston.

And one night after that game-ending obstruction call, another unusual ending. Koji Uehara picked off rookie pinch runner Kolten Wong of Hilo at first base for the final out — with postseason star Carlos Beltran standing at the plate.

Game 5 is Monday night at Busch Stadium, with Boston left-hander Jon Lester facing Cardinals ace Adam Wainwright in a rematch of the opener won 8-1 by the Red Sox.

Gomes helped get Boston started in the fifth when he followed David Ortiz’s leadoff double with a 10-pitch walk that tired starter Lance Lynn, who had faced the minimum 12 batters through the first four innings.

Stephen Drew’s sacrifice fly tied the score 1-all, erasing a deficit created when center fielder Jacoby Ellsbury’s third-inning error advanced Matt Carpenter into scoring position for Beltran’s RBI single.

Ortiz, who homered in the first two games of the Series, had three of Boston’s six hits and was the club’s leader, smacking his hands together and screaming at teammates to get going when he pulled into second base on his double. Then, after the fifth inning, he huddled the Red Sox for a pep talk in the dugout.

Not long after, Gomes’ drive put Boston ahead 4-1 in the sixth.

With adrenaline taking over, Gomes spiked an arm through the air as he rounded first base, yelled and banged his chest with a fist twice. Teammates tugged on Gomes’ beard for good luck when he got back to the dugout, including a two-handed pull by Mike Napoli.

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While talk of umpires’ calls dominated discussion following two of the opening three games, this one turned on a manager’s pregame decision.

John Farrell’s original Red Sox lineup didn’t include Gomes, but Victorino’s back had been bothering him since Saturday, so Daniel Nava was moved from left field to right and from fifth to second in the batting order. Gomes was inserted into the No. 5 hole behind Ortiz.

Gomes had been 0 for 9 in the Series before the home run, and Red Sox outfielders had been 4 for 40 with no RBIs. Following Dustin Pedroia’s two-out single and a four-pitch walk to Ortiz by Lynn, Maness threw five straight sliders to Gomes, who sent the last one into the Red Sox bullpen in left as Matt Holliday kept running back only to run out of room.

Carpenter singled in a run in the seventh off Craig Breslow in the seventh after pinch-hitter Shane Robinson doubled with two outs against Doubront on a ball that skidded away from Gomes. Junichi Tazawa came in and got Holliday to hit an inning-ending grounder to second, a night after allowing a tiebreaking, two-run double to Holliday.

Doubront got the win with 2 2/3 innings of one-hit relief. Lackey, the Game 2 loser and Boston’s probable Game 6 starter, pitched the eighth for his first relief appearance in nine years, overcoming a two-base throwing error by third baseman Xander Bogaerts — Boston’s seventh error of the Series — and a wild pitch.

With a runner on third, Lackey got Jon Jay to pop up and David Freese to ground out.

Uehara, Boston’s sixth pitcher, got three outs for his sixth save this postseason, completing a six-hitter.

Lynn was the hard-luck loser, leaving with the score tied and two on for Maness, who allowed Gomes’ homer on his fifth pitch.