The bet with Campana? Who would get a triple first this season.

“I thought it was the easiest bet I ever made,’’ said Campana, the Cubs’ fastest runner and the majors’ leader in steals with 23.

The Red Sox, meanwhile, lost for the eighth time in 11 games.

“Everyone’s trying,’’ Pedroia said. “We’re not playing good. Today, we didn’t play good.’’

In his second start after Tommy John elbow surgery, Matsuzaka gave up three runs and four hits in six innings before being lifted for a pinch hitter. He walked three — all in the first — but eventually found his rhythm.

The Red Sox simply didn’t give him much support.

They had runners on second and third against Dempster with two out in the seventh, but Pedroia lined to right to end the threat, slamming his helmet in disgust.

Things got tense in the ninth with Marmol on the mound.

Third baseman Luis Valbuena made a diving stop on Jarrod Saltalamacchia’s hard smash to rob him of a hit leading off. But after Ryan Sweeney singled, he misplayed Mike Aviles’ grounder, putting runners on first and second.

Marmol, back in the closer’s job after losing it, then struck out pinch hitter Daniel Nava but walked Scott Podsednik to load the bases, drawing a visit from manager Dale Sveum. He fell behind 2-0 to Pedroia before getting him to bounce to third on a 2-2 pitch to end the game, giving Marmol his first save since May 2 against Cincinnati.

“I feel great up there now,’’ Marmol said. “I feel confidence. I think I’m going to keep my job. I’m going to continue to work hard.’’

Red Sox manager Bobby Valentine was confident, too — that Pedroia would come through.

“I thought Dustin was gonna get him,’’ Valentine said. “I’ll take my chances any time, even though you’d rather not be down three in the ninth any time, but that’s the guy to break him, the ball just hit off the end of the bat.’’