ST. PETERSBURG, Fla. -- Dustin Pedroia hit a two-out, two-strike grand slam in the seventh inning, rallying the Boston Red Sox to a 6-4 victory over the Tampa Bay Rays on Saturday night at Tropicana Field for their 10th straight win.

The Red Sox (91-64) lowered their magic number to clinch a postseason berth to one and took the lead in dramatic fashion as the Rays (65-89) saw their bullpen spoil a strong start by Matt Andriese in taking their fifth loss in six games.

Red Sox starter Rick Porcello (22-4) became the majors' first 22-game winner, and Boston's first since Pedro Martinez won 23 in 1999. The Red Sox are 24-8 in his starts, including wins in 16 of his last 19. He had lasted at least seven innings in 11 straight starts, a streak that ended Saturday when he left in the seventh.

Boston boasts the longest active winning streak in the majors and their longest at any point since 2009. Tampa Bay's Logan Forsythe hit his 20th home run, a solo shot, with two outs in the ninth off closer Craig Kimbrel, who earned his 30th save. Kimbrel had held opponents hitless (0-for-20) over eight appearances.

Andriese left with a 3-2 lead after six innings, but reliever Ryan Garton gave up singles to Hanley Ramirez and Brock Holt to open the seventh. Dana Eveland issued a one-out walk to Jackie Bradley Jr., and the Rays turned to Danny Farquhar with the bases loaded and one out. Sandy Leon grounded into a force play at the plate for the second out, bringing Pedroia to the plate.

Pedroia, who was 2-for-19 on the road trip entering Saturday's game, got behind in the count, ripped a line drive just foul to left field, then had a chopper to third and would-be out that was just foul, keeping himself alive for his fourth career grand slam and 14th home run of the season.

Boston's bullpen got out of a jam in the seventh. Curt Casali and Kevin Kiermaier singled with one out, but Brad Ziegler got Evan Longoria to line out to center field, and Robbie Ross Jr. retired Brad Miller on a liner to right.

The Rays got to Porcello for three runs on a two-out rally in the third inning, and that lead held up at 3-2 entering the sixth inning.

Boston took a 1-0 lead in the second, as Mookie Betts singled and scored on an RBI double by Holt off Andriese.

The Rays nearly tied the game in the second -- Corey Dickerson singled and Nick Franklin doubled -- but on Mikie Mahtook's one-out grounder to second, Pedroia threw home and got Dickerson at the plate.

Tampa Bay jumped ahead 3-1 in the third as Casali and Kiermaier singled, then with two outs, scored on a two-run double by Miller. Miller then scored on an RBI single by Dickerson.

The Red Sox cut the lead to 3-2 in the fourth as Betts walked, stole second for his 26th steal of the season, and scored on an RBI single by Ramirez.

Andriese held the Red Sox to two runs and four hits in six innings.

NOTES: Before facing Porcello on Saturday, the Rays had faced 20-game winners four times before in their history and went 4-0 against them, beating the Yankees' Roger Clemens twice in 2001, Toronto's Roy Halladay in 2003 and the Angels' Bartolo Colon in 2005. ... Boston's Hanley Ramirez (29 home runs, 109 RBIs) needs one home run join teammates David Ortiz (37, 124) and Mookie Betts (31, 108) as the first trio in Red Sox history to reach 30 and 100 in the same season. ... Boston has clinched a postseason berth twice before at Tropicana Field -- in 2004 and 2007. The Red Sox also advanced from the 2013 AL Division Series by beating the Rays in Game 4 in St. Petersburg.