WASHINGTON — Tanner Roark struck out a career-high 15 and allowed only two hits in seven innings Saturday as the Nationals shut out the Twins 2-0.

Roark (2-2) twice struck out the side and fanned two in four other innings. It was only the second time in 52 career starts the right-hander had reached double digits in strikeouts.

“I was throwing four pitches to lefties and righties,” Roark said. “Keeping them guessing, uncomfortable at the plate.”

Roark said he never felt so sharp on the mound, and the numbers backed up the assessment.

He threw a career-high 121 pitches, 78 of them strikes. He walked three, got all but six outs via strikeouts and held the Twins hitless over his final five innings. The 15 strikeouts were five more than he totaled in his first three starts.

Roark and three relievers combined for 18 strikeouts, the most since the franchise arrived from Montreal in 2005.

Blake Treinen and Oliver Perez worked the eighth. Jonathan Papelbon got three outs to complete the combined two-hitter and earn his seventh save.

Ryan Zimmerman drove in two runs and Bryce Harper had a pair of doubles for the Nationals, whose 13-4 start matches the 1981 Expos and 2012 Nats for the best in franchise history.

By striking out 18 times, the Twins tied a club record for most strikeouts in a nine-inning game. Seven of the Twins starters struck out twice. Miguel Sano struck out three times and Joe Mauer once.

The Twins' lone hits were a single by Mauer in the first inning and a double by Max Kepler in the second.

The defeat dropped the Twins to an AL-worst 5-13.