After giving up five runs -- all earned -- over three innings in his Double-A debut on Saturday, Red Sox prospect Stolmy Pimentel cruised through five scoreless frames for Portland on Friday, allowing two hits and a walk while striking out three in the Sea Dogs' 2-1 loss to the New Britain Rock Cats.

The 21-year-old righty, who's considered one of Boston's top pitching prospects, retired the first five batters he faced. After a two-out walk and stolen base by Yangervis Solarte in the second inning, Pimentel moved on by getting Deibinson Romero to fly out to right field.

In his last start, a 13-5 loss to the Reading Phillies, Pimentel allowed four of six baserunners who reached second base to score and also surrendered a home run. Three of the R-Phils' runs came with two outs. Pimentel was less easily shaken in his second Double-A start.

After forcing New Britain to strand Solarte on second early on, Pimentel plowed through six straight, striking out two -- including Twins prospect Joe Benson. He got the opportunity to show his resilience again in the fifth, when he gave up his first hit of the game.

Solarte poked a one-out single up the middle, and Romero followed with a double over the head of Portland center fielder Che-Hsuan Lin. Pimentel responded by whiffing Allan de San Miguel on a changeup in the dirt and getting Chris Cates to dribble a grounder to short.

Pimentel, a Futures Game selection last year, worked through a hit-or-miss 2010 season in the Carolina League. He threw six no-hit innings for Salem on May 15 and again on May 27, but he was tagged for five runs or more in four or fewer innings on three separate occasions. He never went deeper into a game than seven innings.

Boston catching prospect Ryan Lavarnway, in the lineup as designated hitter, knocked in the Sea Dogs' lone run on Friday.

Twins farmhand Steve Singleton plated Solarte with a bloop single to right with two outs in the ninth inning to win the game for New Britain.