Hunter Greene struck out 12 in six innings and Tyler Stephenson went 2-for-3 with two RBIs in his season debut as the Cincinnati Reds defeated the visiting Washington Nationals 6-1 on Friday.

Greene (4-2) limited Washington to one run on two hits and was within two strikeouts of matching his career high. Stephenson, a catcher who was the designated hitter on Friday, was activated from the injured list earlier in the day after recovering from a left oblique strain.

Nationals starting pitcher Mitchell Parker (3-2) gave up five runs on four hits and walked four in four innings. Washington has lost five of its past seven games.

The Reds have won two straight and seven of their last nine.

The lefty Parker struggled with command early, and Cincinnati took advantage.

In the first inning, he gave up a pair of one-out walks to Matt McLain and Elly De La Cruz. With two outs, Santiago Espinal doubled to left field to bring them both in.

Stephenson drew a leadoff walk in the second. Blake Dunn was hit by a pitch with one out, and TJ Friedl loaded the bases with a single through the first base gap. McLain's fielder's choice grounder scored Stephenson to make it 3-0.

The Reds padded their advantage in the third. With one out, Espinal walked, Spencer Steer singled and Stephenson doubled to drive drove both home to push it to 5-0.

Parker got Cincinnati out in order in the fourth before being replaced to start the fifth inning.

The Nationals struggled to get on base against Greene, who held them to one hit and one walk through the first four innings.

They finally got on the board in the fifth when Josh Bell belted a solo shot to right-center field for his fifth home run of the season.

But Greene held firm for the rest of his outing, holding Washington to only one more baserunner on a walk in the sixth.

The Reds added another run in the sixth. Stephenson opened with a ground-rule double to left-center field, Jose Trevino followed with a single, and Friedl drove in Stephenson with a sacrifice fly.