The Trenton Thunder clinched an Eastern League playoff berth by scoring two runs in the 15th inning to pull out a 4-2 win over the Portland Sea Dogs in the annual “Field of Dreams” game Saturday night at Hadlock Field.

The teams were knotted at 2-2 after the Sea Dogs scored two runs in the bottom of the fifth.

In the 15th, though, Thunder leadoff batter Tyler Wade reached on an error by second baseman Ryan Court. He stole second with one out and was trying to steal third when Miguel Andujar sent a ground single into left, driving home Wade with the go-ahead run. Two-out singles by Mark Payton and Billy McKinney produced another run.

Portland put two runners on with nobody out in the bottom half as Cole Sturgeon walked and Mauricio Dubon was hit by a pitch, but J.P. Feyereisen (7-3) struck out the next three batters. Four Trenton relievers combined for 17 strikeouts in 92/3 innings, as the Sea Dogs finished with 21 strikeouts.

The Sea Dogs threatened to end the game in the 12th when Rainel Rosario hit a double to deep center with one out. After Yoan Moncada was walked intentionally, Sturgeon bounced a single into left field, but Rosario had to stop at third. Tyler Jones then got Dubon to hit into a force play at home and retired Aneury Tavarez on another grounder.

Boston Red Sox catcher Ryan Hanigan, currently on the 15-day disabled list, started behind the plate for the Sea Dogs as he began a rehab assignment. Hanigan was placed on the DL on Aug. 8 because of left ankle tendinitis. He went 0 for 3 with walk and an RBI groundout before leaving the game after seven innings, and is expected to serve as the designated hitter for the Sea Dogs’ final home game of the season Sunday.

The Thunder took a 1-0 lead in the fourth. With two outs, Payton doubled into the gap in right, and McKinney and Abiatal Avelino followed with singles. Trenton made it 2-0 when Sebastian Valle, Wade and Dustin Fowler led off the fifth with singles.

The Sea Dogs pulled even in the bottom of the fifth. Cody Decker capped an 11-pitch at-bat with a leadoff double to left and moved to third on a ground ball by Henry Ramos. Moncada’s single through the right side and Hanigan’s grounder to shortstop produced the runs.

The Sea Dogs wasted a chance to break the tie in the seventh when Ramos led off with a double and moved to third on Rosario’s sacrifice. Moncada was walked intentionally, then was caught stealing, and Hanigan took a called third strike on reliever Matt Wotherspoon’s 3-and-2 slider.

Both teams got strong relief pitching.

Trenton relievers Giovanny Gallegos and Jones struck out eight of the nine Portland hitters in the eighth, ninth and 10th innings.

Ben Taylor, Portland’s workhorse reliever, retired eight of the nine men he faced after coming in with one out in the 10th.

Sea Dogs starter Teddy Stankiewicz allowed seven hits and two runs in five innings.

NOTES: The Sea Dogs drew their 12th sellout crowd of the season – 7,368. About 125 tickets remain for the final home game at 1 p.m. Sunday. … Tavarez, the league’s leading hitter, was selected to the season-ending Eastern League All-Star team. … Moncada, who batted .307 with 36 stolen bases in 61 games for Class A Salem before getting promoted, was named to the Carolina League All-Star team with third-base prospect Rafael Devers.