Instant analysis: Nats 9, Orioles 3

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Nate Karns allowed three runs over 4 2/3 innings in his big-league debut.

Game in a nutshell: The evening began as a highly touted matchup of young right-handers, Nate Karns and Kevin Gausman, but was more notable by night's end for the Nationals' rare offensive explosion. Karns did what he needed to do, churning out 4 1/3 solid innings before tiring in the fifth. Gausman, though, was roughed up by the Nationals for three runs in the first, then four more in the fourth before he was knocked out. Adam LaRoche crushed two homers, and Tyler Moore and Roger Bernadina went back-to-back in a rare display of firepower from the reserves-turned-starters. Needing 4 2/3 innings out of his bullpen, Davey Johnson got quality work out of Zach Duke (who was credited with the win), Drew Storen, Tyler Clippard and Fernando Abad. So the Battle of Beltways is now even at 1 game apiece, heading into Phase 2 the next two nights at Camden Yards.

Hitting highlight: The Nationals have been begging, pleading for their bench players to produce with several starters injured. On this night, Moore and Bernadina finally delivered. Back-to-back. Moore, who entered the evening with a .152 batting average and one home run, crushed a hanging, 0-2 slider from Gausman to left field for a two-run homer. Seconds later, Bernadina, who entered with a .121 batting average and one RBI for the season, belted a homer to right. It's only one game, obviously, but if the Nationals can continue to get anything remotely close to decent production out of those two, they can survive the injuries to Bryce Harper and Jayson Werth.

Pitching highlight: The final numbers (4 1/3 innings, 5 hits, 3 earned runs) are a bit misleading, because Karns pitched much better than that would indicate, especially for someone thrust into that situation. The 25-year-old rookie, fresh out of Class AA, showed some real poise, not to mention exceptional stuff, in his big-league debut. Karns consistently hit 95 mph with his fastball and topped out at 97 mph, while also displaying some nice offspeed pitches. He did groove a couple of fastballs in the fourth inning, resulting in homers by Chris Davis and J.J Hardy, but he also came through with some big pitches when he needed them. Johnson would have loved for the kid to go five innings and qualify for the win, but Karns hit a wall in the top of the fifth. He walked Nate McLouth and Manny Machado in succession, and with Nick Markakis due up, Johnson decided to turn to his bullpen. Karns walked off the field to a thunderous roar from the crowd of 35,664. He's ticketed to go back to Harrisburg, but rest assured, we'll be seeing him again in D.C. sometime in the near future.

Key stat: LaRoche is hitting .341 with a .422 on-base percentage, seven homers and 19 RBI in the month of May.

Up next: The series now shifts north about 45 miles for the next two nights. Jordan Zimmermann will be seeking his NL-leading ninth win when he takes the mound at 7:05 p.m. Wednesday Camden Yards against Chris Tillman.