Seager is batting .319 in spring training and the Mariners have scored 40 runs in their past five games.
''We swung the bat very well. A number of guys. It's not just one or two guys carrying the club every day,'' Mariners manager Scott Servais said. ''Seager's played a lot the last couple of days. His timing looks really good.''
Seth Smith homered for the Mariners and starter Wade Miley went six innings, allowing three runs on eight hits with five strikeouts. Seattle closer Steve Cishek struggled through the ninth, giving up two runs on three hits, but was able to avoid further damage and preserved the win with strikeouts of the last two batters he faced.
''To his credit, he made pitches at the end when he did and he executed, which was good to see,'' Servais said.
The Dodgers hit into three double plays against Miley.
''I was able to get some ground balls when I need them, make pitches when I needed to,'' Miley said. ''I tried to treat today as game-like as possible. It's the last long (start) before the season so I really wanted to just go out there and try to win.''
Seager had three hits and a stolen base, and Marte was 2 for 3 from the leadoff spot with a homer in the fifth inning. He sprawled on his back with his arms raised after crossing home plate.
Dodgers starter Scott Kazmir gave up two runs on five hits and struck out five in four innings.
''Figured something out after the first inning, just was drifting a little bit, that's why everything was finishing on the wrong side,'' Kazmir said. ''It's kind of something I've had a problem with pretty much all spring. Kind of really identified it and everything just got a little more crisp after that.''
Kazmir had an abdominal issue and exited early as a precaution, the Dodgers said. Later, the team announced he had cramps caused by dehydration.
Dodgers President of Baseball Operations Andrew Friedman said the club's medical staff confirmed Kazmir did not have a serious problem.
Expected to be the team's No. 2 starter, Kazmir made his fourth spring training start. He'd given up eight earned runs on 16 hits in 7 2-3 innings before Saturday.
A.J. Ellis drove in two runs and Scott Van Slyke had three hits for the Dodgers.
IWAKUMA WORKS IN MINOR LEAGUE GAME
Hisashi Iwakuma, the Mariners' No. 2 starter, pitched in a minor league game Saturday at the Mariners' complex that was going on at the same time as the major league game. He threw six innings, allowed five runs on six hits and struck out six on 81 pitches. Iwakuma's next outing will be another minor league start.
''They jumped on the fastball early but from the fifth inning on, I was able to pitch more with a better rhythm and tempo. I think I had better arm action with my fastball,'' Iwakuma said. ''Overall I was able to finish the game pretty well.''
Dodgers: OF Yasiel Puig was scratched because of tightness in his left hamstring. The Dodgers say the move was precautionary, and they consider Puig day to day.
Puig woke up Saturday with a tight hamstring after exiting a 13-0 victory over the Giants on Friday night after hitting a double in the second inning.
Manager Dave Roberts said he would ''err on the side of caution'' because he wanted Puig to be ready for opening day. A tight hamstring put Puig on the disabled list twice last season.
Puig was replaced by minor leaguer Jacob Scavuzzo, who played left with Van Slyke moving to right and hit a home run.
Dodgers: The Dodgers have been riddled with injuries in spring training, and Kazmir was feared to be the latest. But he said he is fine and will ''no doubt'' make his next scheduled start on March 31.
''It's really nothing to even kind of identify,'' Kazmir said. ''This is just one of those things where everything was going great and I felt comfortable to go back out there but the guys made a decision to just shut it down.''
Mariners: Miley called his day a success, even against Van Slyke, who has five home runs and three doubles against him in his career from when Miley was with the Arizona Diamondbacks. Van Slyke had three hits off Miley on Saturday.
''Been an ongoing process for a while,'' Miley said. ''That was actually a good day against Van Slyke. Three singles? That's a good day. Be glad he's in the NL West, we don't play those guys.''
Dodgers: RHP Kenta Maeda, in position for the No. 3 spot in the starting rotation when the regular season begins, is scheduled to pitch against the Cincinnati Reds and Alfredo Simon on Easter Sunday.
Mariners: James Paxton makes his latest case for the yet-undecided fifth rotation spot on Sunday against Jason Hammel and the Chicago Cubs.