SEATTLE -- When Chris Sale went to sleep Tuesday, the night before he was to pitch a day game at Safeco Field, his Boston Red Sox were still playing.

He didn't learn the Red Sox had lost their season-high fourth straight game -- 6-5 in 13 innings, a game which lasted 4 hours, 59 minutes and finished after midnight -- until Wednesday morning.

Sale stopped the skid, pitching seven scoreless innings and striking out 11 as the Red Sox defeated the Seattle Mariners 4-0 Wednesday afternoon.

"You want to cut those (losing streaks) as short as you can," Sale said. "With an off day (Thursday) and a long flight home it was good to get this one."

Was the losing streak weighing on Sale's mind?

"I don't want to be thinking a whole lot out there," he said. "It's not my game."

Rookie Rafael Devers and Sandy Leon hit home runs for Boston. It was Devers' first major league hit.

Devers, the organization's top prospect, was playing in just his second game after being called up from Triple-A Pawtucket. He led off the third inning with a 427-foot blast to center field off Mariners rookie right-hander Andrew Moore (1-3).

"I knew it was going out, but I have to run hard out of the (batter's) box," Devers said through a translator. "It was surreal when I got back to the dugout. I could hardly walk."

Leon added a two-run shot off Moore in the fourth inning, capping the scoring.

That was more than enough for Sale (13-4), who didn't allow a run for the fourth time in his past five starts, pitching six or more innings in each of those appearances. It also was his 14th game with double-digit strikeouts this season.

"He's had a start like today a number of times this season," Red Sox manager John Farrell said. "We're watching one of the best years by a major league pitcher."

The left-hander, who started the All-Star Game for the American League, didn't allow a hit the first time through the Mariners batting order.

Seattle leadoff hitter Jean Segura ripped a double down the left-field line with one out in the third. Sale struck out the next two batters to strand Segura.

The Mariners' Guillermo Heredia got a hustle double with two outs in the fourth, beating the throw to second on a ball hit into left-center field. Sale got Mitch Haniger to foul out to first baseman Mitch Moreland to end that inning.

Seattle's Ben Gamel led off the sixth with a single to cap a 10-pitch at-bat, with Gamel fouling off several two-strike pitches before extending his hitting streak to 13 games. Sale responded by getting Nelson Cruz and Danny Valencia, the Nos. 3-4 hitters in the Seattle lineup, to look at called third strikes and Kyle Seager to pop out to second.

That was it for the Mariners against Sale, who improved to 5-1 against Seattle in his career -- including 3-0 at Safeco Field.

"When he got guys on base he reared back and got something in the tank," Farrell said. "He's such a competitor. Whether it's a four-game winning streak or a four-game losing streak, you get the same performance: dominance."

Blaine Boyer pitched a scoreless eighth for Boston and got the first out in the ninth, but then allowed a single to Seager and walked Heredia, forcing John Farrell to bring on Craig Kimbrel. The closer had thrown 30 pitches in Tuesday night's 13-inning game.

Kimbrel struck out Haniger and Carlos Ruiz to end it, earning his 25th save of the season.

Moore went 6 2/3 innings for the Mariners, allowing four runs on six hits. He walked one and struck out three.

"After a crazy game last night, we ended up going up against Sale and we knew that was going to be a tight game," Mariners manager Scott Servais said. "There's a reason he's been the most dominating pitcher in the American League and we saw that today."

NOTES: The teams split the season series 3-3, with five of the games finishing in shutouts. The Red Sox blanked the Mariners three times. ... The Red Sox sent minor league RHPs Shaun Anderson and Gregory Santos to San Francisco in the trade for INF Eduardo Nunez late Tuesday night. To make room on the 40-man roster for Nunez, Boston designated LHP Luis Ysla for assignment. The Red Sox also activated RHP Blaine Boyer from the 10-day disabled list and placed RHP Ben Taylor on the DL with a left intercostal strain. ... The Red Sox and Mariners are both idle Thursday. Boston returns home for a three-game series with Kansas City, starting Friday at Fenway Park. LHP David Price (5-3, 3.82 ERA) is scheduled to start for the Red Sox. The Mariners will host the New York Mets in a three-game weekend series. LHP Ariel Miranda (7-4, 4.30) is scheduled to start the opener Friday night.