Jorge Polanco and Mitch Haniger hit homers as the Seattle Mariners set a season high in runs during a 9-3 victory against the visiting Cincinnati Reds on Monday night in the opener of a three-game interleague series.

Jeimer Candelario and Jake Fraley went deep for the Reds, who had a three-game winning streak snapped.

Mariners right-hander George Kirby (2-2), who lost his previous two starts, went six innings and allowed two runs on five hits with no walks and six strikeouts.

Reds starter Frankie Montas (2-2) struggled with his command and lasted only two-plus innings. The right-hander allowed five runs on three hits with five walks and one strikeout. Montas threw 66 pitches -- 45 in the first inning alone -- with just 34 finding the strike zone.

Montas walked the first two batters in the first inning before Polanco hit a 3-1 fastball over the wall in right-center field. The three runs scored by the Mariners were one more than they had scored in the first inning in their first 16 games combined.

Candelario went deep to center with two outs in the second to pull the Reds within 3-1.

The Mariners extended their lead in the third as Polanco led off with a walk and Haniger deposited a 1-0 cutter over the wall in left-center, ending Montas' night.

The Reds scored in the fourth as Christian Encarnacion-Strand led off with a double into the left field corner and, an out later, Fraley dumped a check-swing double just over third base.

Ty France led off the bottom of the sixth with a double to left, took third on Cal Raleigh's single to center and scored on Jonatan Clase's grounder to left. It was the first hit and RBI for Clase, who was making his major league debut.

Fraley homered off reliever Gabe Speier leading off the seventh to pull the Reds within 6-3.

Seattle scored three times in the bottom of the inning off Buck Farmer to pull away. Julio Rodriguez blooped a single to right and stole second. Polanco walked and Haniger grounded a run-scoring double to left. France brought in another run with a sacrifice fly and, with two outs, Luke Raley laced a run-scoring triple to left.

The Mariners' previous best for scoring this season came in a 6-1 victory in 10 innings at Toronto on Wednesday.

--Field Level Media