SEATTLE -- Seattle Mariners starter J.A. Happ got an early lead and some solid defense on the way to earning his third victory of the season Saturday night.

The same couldn't be said for Jesse Hahn and the mistake-prone Oakland A's.

Four Oakland errors opened the door for a big early lead on the way to the Mariners' 7-2 win over the struggling A's.

"You're not going to win any games making four errors," frustrated A's manager Bob Melvin said afterward.

Second baseman Robinson Cano and right fielder Nelson Cruz combined for five hits as the Mariners (13-17) won consecutive games for the first time since sweeping the Texas Rangers in a three-game series April 27-29. Cano went 3-for-5 with an RBI and two runs for the Mariners. Cruz was 2-for-3 and also reached on a walk and a hit by pitch.

Lloyd McClendon won his 100th game as Seattle's manager.

"Talk to me when I get to 1,000," McClendon said before getting a beer shower from the Mariners players to commemorate the milestone.

Oakland (12-20) has lost four straight and five of its past six games, going 4-12 since April 22.

"Based on our record right now, and some of our losses, it's not a good feeling," Melvin said.

Cano did all of his damage as Seattle built a 6-1 lead in the first six innings. Happ (3-1) had another strong outing while allowing four hits and one run in five innings.

"To, early in the game, have a three-run lead was awesome," Happ said. "That was good to see out of our guys."

Oakland's Hahn went 5 1/3 innings, allowing eight hits, four earned runs and two unearned runs before 32-year-old reliever Angel Castro came on to make his major league debut in the sixth.

Castro struck out the first batter he faced, then gave up an RBI single to Cano and walked Cruz before getting out of the inning with a long flyout off the bat of Seattle third baseman Kyle Seager.

Oakland's four errors led to two unearned runs, and the mistake-plagued A's also had two wild pitches and issued six walks and two hit batters.

"When you put on extra guys on base, that makes it difficult," Melvin said, adding "whether it's an error or it's a walk."

A's first baseman Mark Canha hit his fifth home run of the season. His solo shot in the eighth inning cut the Seattle lead to 6-2. The Mariners tacked on a run when pinch hitter Justin Ruggiano scored on a wild pitch in the eighth.

Oakland shortstop Marcus Semien had three hits and two stolen bases, and center fielder Billy Burns and second baseman Eric Sogard each had two hits for the A's. Nine of Oakland's 10 hits were singles.

NOTES: During the game, Oakland acquired reliever Edward Mujica from the Boston Red Sox for a player to be named. Mujica, whose 31st birthday is on Sunday, was 1-1 with a 4.61 ERA in 11 appearances with Boston. ... A's RHP Jarrod Parker, who was making his fourth rehab start while trying to come back from Tommy John surgery, suffered a serious elbow injury Friday night. Parker hurt the elbow while throwing his 87th pitch of a game for Triple-A Nashville. His prognosis for playing again this season was unknown as of early Saturday night. ... Oakland reinstated 1B Nate Freiman from the 15-day disabled list and optioned him to Triple-A Nashville. He had been on the DL since Opening Day because of a strained lumbar muscle. ... Lloyd McClendon went into Saturday night's game with 99 wins as Mariners manager. ... Seattle rescinded its roster move earlier in the week that sent LHP Tyler Olson to Triple-A Tacoma. A medical examination revealed a bruised right knee and Olson was placed on the 15-day disabled list retroactive to May 3.