David Ortiz came up big for Boston in Game Two. Reuters

The Boston Red Sox came back from five runs down to split the American Champions League Series with the Detroit Tigers in Game Two at Fenway Park on Sunday night, 6-5.

David Ortiz hit a grand slam off Joaquin Benoit in the eight inning to help lead Boston to an improbable victory. Catcher Jarrod Saltalamacchia drove in Jonny Gomes with a single to left in the bottom of the ninth off Rick Porcello for the game-winning run.

The Tigers squandered an excellent pitching performance from Max Scherzer. The starter allowed just one run off two hits, and struck out 13 in seven innings, but the Detroit bullpen couldn't protect the lead. Jose Veras, Drew Smyly, Al Alburquerque, Benoit, and Porcello each allowed a baserunner after Detroit built up a solid lead entering the bottom of the eight inning. Alex Avila drove in three runs for Detroit.

The series shifts to Detroit on Tuesday for Game Three. The Tigers finished with a 51-30 record at Comerica Park in the regular season. The Tigers split two home games with the Oakland A's in the American League Division Series.

John Lackey takes the mound for the Red Sox, while the Tigers go with former Cy Young winner Justin Verlander.

In the National League, the St. Louis Cardinals pitching staff have allowed just two runs in 22 innings to build a 2-0 series lead over the Los Angeles Dodgers. After beating L.A. in 13 innings on Friday, 3-2, the Cards held off the Dodgers 1-0 in Game Two by allowing just five hits and one walk. Second baseman Mark Ellis was the only Dodger batter to earn an extra base hit.

The series moves to Dodger Stadium on Monday for Game Three. Don Mattingly's squad may need a better effort from star rookie Yasiel Puig to get back into contention. The talented Cuban has failed to get on base in 10 at-bats in the series, and has struck out six times.

Ace Adam Wainwright will be on the mound for the visitors, while rooke Hyun-Jin Ryu gets the nod for L.A.