SEATTLE -- Boston Red Sox manager John Farrell didn't even wait for the first question to be asked.

He stood in front of the media after a 2-1 loss Friday to Seattle and admitted that he'd made a mistake by pitching to Mariners slugger Nelson Cruz with first base open in the bottom of the ninth inning.

"That's a terrible decision on my part," Farrell said before reporters got a chance to begin their inquisition. "I own up to it."

Rather than avoid pitching to the top hitter in the American League, Farrell and the Red Sox went right at Cruz with two outs and a runner on second base -- and it cost them.

Cruz's two-out, RBI single with a runner on second base drove in the winning run in the bottom of the ninth inning.

"You never know what's going to happen," Cruz said when asked whether he was surprised that the Red Sox pitched to him. "I like the challenge. I want to hit in that spot."

With two outs and a runner on second base, right-handed reliever Junichi Tazawa was brought in to face Cruz. Tazawa (0-2) gave up a long single into the gap between left and center field to score Brad Miller easily from second.

Cruz, who ranked among the AL's top two in batting, RBIs and home runs entering the game, said that when Boston replaced left-handed reliever Tommy Layne with Tazawa, he knew the Red Sox were going at him. While left-handed batter Kyle Seager watched from the on-deck circle, Cruz drew counts of 2-1 and 3-2 before he lined a rope between left fielder Hanley Ramirez and center fielder Mookie Betts for a single that would have easily gone for extra bases had it not ended the game.

"It's part of the game," Cruz said. "Whatever they think, that's what they're going to do."

Farrell semi-explained the decision by bringing up Cruz's three strikeouts during his first three at-bats of the game, as well as his 1-for-8 history against Tazawa. But Farrell wasn't trying to make any excuses.

"It didn't work out," he said. "That's a horrible decision on my part."

The loss spoiled an excellent start from Boston right-hander Clay Buchholz.

Buchholz allowed just three hits over eight innings, with the only run against him coming on a solo home run by Seattle right fielder Seth Smith with two outs in the sixth. Buchholz struck out 11 without issuing a walk but didn't factor into the decision.

"He had command, he threw a lot of strikes, he had every pitch working for him tonight," Farrell said.

Having given up a two-out double in the bottom of the first, Buchholz had retired 15 consecutive batters before Smith finally broke through with a 419-foot solo shot to centerfield in the sixth. The homer, Smith's third of the year, tied the score 1-1.

Mariners starter J.A. Happ matched Buchholz for seven innings, allowing one earned run off five hits.

Seattle's Miller had a one-out, infield single in the ninth to start the Seattle rally. One out later, with first base open, Tazawa came on and challenged Cruz, who delivered with the game-winner after striking out in his previous three at-bats.

The Mariners (16-19) won for the fifth time in six games, while Boston (17-19) had its two-game winning streak snapped.

Shortstop Xander Bogaerts gave the Red Sox a 1-0 lead with a two-out, RBI triple in the top of the second inning. With right fielder Shane Victorino on second base, Bogaerts hit a 3-2 pitch off the top of the wall in right center to drive in the first run of the game.

Boston threatened again in the fourth when the Red Sox had runners at the corners with one out, but Seattle's Happ escaped that jam when a baserunning gaffe by Victorino led to a 1-3-6-2-5 tag of Mike Napoli between third base and home plate.

Buchholz gave up a two-out double in the first inning before retiring 13 consecutive batters through the fifth to preserve the 1-0 lead for the Red Sox. Of the 15 outs Buchholz recorded over the first five innings, only three came on balls hit out of the infield.

"Clay pitched outstanding tonight," Farrell said. "A dominating performance. We didn't have a lot of offense, but the decision in the ninth inning was the story."

NOTES: Seattle started four right-handers against Buchholz on Friday night, and that was by design. Right-handed hitters were hitting .364 against Buchholz heading into the game. ... RHP Felix Hernandez, who is scheduled to start Saturday's game for the Mariners, is off to the best start of his career. He is 6-0 with a 1.85 ERA and could become the first Seattle starter since Aaron Sele in 2001 to go 7-0. ... The Red Sox haven't been at .500 since May 2. ... Seattle's Happ has allowed two runs or fewer in six of his seven starts this season.