SEATTLE -- Tape-measure home runs are commonplace at Coors Field in the mile-high air of Denver.

Not so at Safeco Field.

But the Colorado Rockies' Mark Reynolds proved Thursday afternoon it can be done, hitting a 450-foot shot off Seattle starter Yovani Gallardo (2-6) in the second inning.

That blast sparked the Rockies to a 6-3 victory over the Mariners that snapped Colorado's three-game losing streak. Nolan Arenado also homered for Colorado.

The injury-ravaged Mariners saw their winning streak snapped at four games, which matched a season high, and had shortstop Jean Segura and designated hitter Nelson Cruz leave the game early.

Cruz was hit on the left hand by a pitch from Colorado's Kyle Freeland (6-3) in the third inning, and Segura appeared to twist his right ankle while sliding into second base in the fourth.

Mariners manager Scott Servais said both Segura, who is tied for the American League lead in batting at .341, and Cruz, the AL leader with 42 RBIs, will undergo further examination and an update on their injuries likely won't come until Friday.

"Hopefully they're not out any amount of time. We need them," Servais said. "Injuries happen. We've been dealing with them all year."

Freeland, who allowed two runs on six hits in six innings, hit three batters.

"The one to Cruz was the only one that got away," the rookie left-hander said. "It was a cutter and I choked it."

Reynolds' homer, a two-run shot that snapped a scoreless tie, was the longest hit in Seattle this season. It exceeded a 448-foot blast by Miami's Giancarlo Stanton on April 19.

Reynolds' homer cleared the Seattle bullpen and the out-of-town scoreboard in left-center field and just missed reaching the second deck. It was Reynolds' 14th home run of the season.

"That was a bomb," Rockies manager Bud Black said. "That was a big one."

Said Reynolds: "When you swing hard and barrel up a high heater, it's going to go a ways."

The Rockies scored four runs in the second.

Arenado added a solo shot, his 13th of the season, leading off the third. The ball landed in the Rockies' bullpen in left field.

Seattle's Guillermo Heredia hit a solo home run in the second inning, his fourth of the season.

The Mariners scored in the seventh off Rockies reliever Chris Rusin and brought the potential tying run to the plate. But with two runners on, Rusin got Kyle Seager to pop out to shortstop Trevor Story and struck out Heredia to end the threat.

After the Rockies' Jake McGee pitched a scoreless eighth, Greg Holland came on to get his major-league-leading 20th save in as many opportunities.

NOTES: Colorado LF Gerardo Parra went 4-for-4 with a double and an RBI. ... Seattle RHP Casey Lawrence allowed one run on three hits in five innings of relief, striking out nine. ... The Rockies next head to San Diego for a three-game series. RHP German Marquez (4-2, 3.76 ERA) is scheduled to face Padres LHP Clayton Richard (3-6, 4.33 ERA) in the opener Friday. ... Seattle stays at home this weekend to face Tampa Bay. RHP Christian Bergman (2-2, 4.67 ERA) is set to match up against Rays RHP Jake Odorizzi (3-2, 3.14 ERA) to begin the three-game series.