Game in a nutshell: The first matchup between winning ballclubs from Washington and Baltimore in 42 years lived up to the billing, with Edwin Jackson and Jake Arrieta dueling each other on the mound. Jackson gave up one early run, then cruised. Arrieta cruised until serving up a solo homer to Ian Desmond in the sixth. That left this game in the hands of both bullpens. Tyler Clippard did his part in the top of the ninth, then Darren O'Day and Troy Patton retired the heart of the Nats' lineup in the bottom of the inning, sending this one to extras. That's when Nick Markakis took matters into his own hands, crushing a pitch from Ryan Mattheus off the facing of the second deck down the right-field line to give the Orioles an 11-inning victory before an energetic crowd of 36,680.
Hitting lowlight: They tried all night to get something going at the plate. In the end, Desmond's solo homer in the sixth represented the entirety of the Nationals' offensive effort. There were missed opportunities, and there was plenty of poor execution, especially during a failed seventh-inning rally. After Bryce Harper led off with a walk, Danny Espinosa fouled off a bunt with two strikes and Rick Ankiel and Jesus Flores each popped out.
Pitching highlight: The night started off really poorly for Jackson, who walked Xavier Avery to open the top of the first and then fell behind No. 2 hitter J.J. Hardy 3-0. But credit to the right-hander for bouncing back in a big-time way after that. Jackson didn't walk another batter all night and struck out eight over eight splendid innings. He also kept his pitch count to a relatively low 95, flashing shades of his complete-game win from last month.
Key stat: Desmond now has six homers. The only major-league shortstop with more this season is the Orioles' Hardy (nine).
Up next: Game 2 of this interleague series features a couple of starters who have surprised so far this season. Left-hander Ross Detwiler (3-2, 2.75) starts for the Nats against right-hander Jason Hammel (4-1, 2.68) for the Orioles. First pitch is at 7:15 p.m., with the game televised on Fox.
WASHINGTON -- Anthony Rendon homered twice and drove in five runs, Joe Ross returned from the minors to allow one run over a career high-tying eight innings, and the Washington Nationals routed the Seattle Mariners 10-1 on Tuesday night.
Bryce Harper added his 14th homer and Jayson Werth hit his seventh off Chris Bergman (1-2), who allowed all of the Nationals' runs and 14 of their 15 hits.
Rendon doubled before his second homer -- and seventh of the season -- completed an eight-run fourth inning. Ryan Zimmerman also had three hits.
Mike Zunino homered off Ross (2-0) in his return from his own minor league stint. Robinson Cano was hitless in his first game back from the disabled list following a thigh injury as Seattle dropped its fourth straight.
Ross showed no signs of the late April struggles that ended with a demotion to Triple-A Syracuse. He yielded five hits and a walk while striking out six, and retired 12 straight batters after a leadoff single to begin the game.
By the time Seattle finally put multiple runners aboard, Washington had already opened a 10-0 lead.
Rendon's second-inning shot around the left field foul pole made it 2-0.
Then Werth, Harper and Rendon all connected in the fourth, helping the Nationals score seven of their eight runs in the inning with two outs.
MORE NATIONALS: WATCH: Werth, Harper go back-to-back, Rendon hits 2 HRs in Nationals win
The Nationals had a big day at the plate Tuesday night.
Washington hit four home runs, including three in an eight-run fourth inning, in its 10-1 victory over the Seattle Mariners.
Third baseman Anthony Rendon hit two home runs – the first a two-run blast to left field in the second inning and the second a three-run shot to center in the fourth. He finished the game 3-for-4 with five RBIs.
Prior to Rendon’s second homer in the fourth inning, left fielder Jayson Werth hit a two-run blast to left field, which was followed by a solo shot from right fielder Bryce Harper in the next at-bat.
Harper’s homer was measured at 450 feet.
At the end of the fourth, the Nationals led 10-0, which also included an RBI single from catcher Matt Wieters and an RBI triple from shortstop Trea Turner.
Tuesday night’s contest was the first of a three-game home series against the Mariners, who play in the American League. The Nationals and Mariners also will play Wednesday and Thursday.
Earlier this season in a 23-5 win over the New York Mets on April 30, Rendon went 6-for-6 with three home runs and 10 RBIs to become the first player to accomplish that feat since at least 1913. He now has seven homers this season.
Harper’s homer was his 14th of the season, tying him for first in the National League with the Atlanta Braves’ Freddie Freeman. The New York Yankees’ Aaron Judge is first with 15.
Though he did not have a home run Tuesday night, Nationals first baseman Ryan Zimmerman has 13 for the season.
MORE NATIONALS: 2017 MLB Power Rankings: As Bryce Harper goes, so do the Nationals