Hot-hitting O's offense faces the NL wins leader tonight (updated twice)

The Orioles offense, which has produced a batting average of .309 and 5.4 runs per game over the last 17 games, gets a real challenge tonight. They face Nats right-hander Jordan Zimmermann, who is 8-2 with a 1.71 ERA in 10 starts. He has allowed two earned runs or less in seven straight starts, recording nine quality starts on the season. Zimmermann has pitched seven innings or more in his last six starts. The O's entire starting staff has gone seven or more just five times all season. Left-handed batters are hitting .234 off Zimmermann and right-handed batters are hitting just .172. In his two losses, he allowed just three earned runs with an ERA of 2.08. He is 5-1 with a 1.16 ERA over his past six starts and the Nationals are 22-6 in his last 28 starts. Did I mention this could be a challenge for the O's hitters tonight? Zimmermann is 1-2 with 2.70 ERA over four starts against the Orioles in his career, squaring off opposite Rich Hill, Chris Tillman (who he faces tonight), Brian Matusz and Jason Hammel. Let's see how some hot-hitting O's fare against him tonight, including Chris Davis, who has 17 extra-base hits (nine doubles and eight homers) over his past 18 games. J.J. Hardy, who is batting .326 his last 23 games, and Manny Machado, who has five multi-hit games over his last seven, going 14-for-32. Zimmermann on the NL leaderboard: * Tied for first with eight wins * Tied for second in ERA at 1.71 * First with three complete games * Fifth in innings at 73 2/3 * Second in WHIP at 0.87 According to Fangraphs PITCHf/x his average fastball is 93.6 mph. Buck Showalter said his excellent fastball command and ability to consistently repeat his delivery has keyed his great year. He said Zimmermann throws a pretty high percentage of fastballs. He ranks second among all NL starters in fewest walks per nine innings at 1.10. Update: In four of his last six starts, Zimmermann gave up just one or zero earned runs. Tonight, through four innings, the Orioles have gotten two off him and trail the Nats 3-2. In his first at-bat since rejoining the team, Ryan Flaherty delivered an RBI double in the second and Davis hit yet another homer in the fourth to pull the O's within 3-2. For Davis, it was his big league-leading 18th. He has hit five over his last eight games, seven in the past 12 and nine in the last 19 games. The Nats hit three solo shots off Tillman to take a 3-2 lead to the fifth tonight. Tillman gets rocked: For the second night in a row, the Nats offense, which has not exactly been tearing the cover off the ball, treated an O's starter rudely. Tillman allowed a career-high four homers, three to Ryan Zimmerman, as the Nats took a 6-2 lead to the sixth. Tillman and Kevin Gausman have allowed 13 runs on 16 hits and seven homers over a combined 8 2/3 innings the last two nights. Tillman had an ERA of 2.62 in his last seven starts.