BALTIMORE -- For all the ups and downs the Nationals' starting rotation has been through this season, the unit entered Wednesday’s series finale against the Orioles on an MLB-best streak of 21 consecutive innings without allowing an earned run.

Washington was coming off a shutout win at Camden Yards, aiming to extend its rotation's dominant run that dated back to the fourth inning of Game 2 of a June 17 doubleheader against the Phillies. Paolo Espino, Josiah Gray, Jackson Tetreault and Erick Fedde had pitched well since then, with Patrick Corbin up next to keep the streak going.

“I love the way we’re attacking the zone now, I really do, from everybody,” Nats manager Dave Martinez said. “Going into today, I didn’t really think about what we’ve done with our pitching staff, even though in the back of my mind I said, 'We’re pitching better,' as I always talk about.”

However, the Orioles played spoiler in the Nationals’ 7-0 loss on Wednesday night, which included a pair of rain delays -- totaling 1 hour and 46 minutes -- before the game was called after six innings.

Well before the downpours, Corbin allowed back-to-back singles to start the bottom of the first inning. He then gave up an RBI double to Ryan Mountcastle to quickly fall into a 1-0 deficit. With the O's fouling off pitches at a high rate, Corbin threw 31 pitches to six batters before ending the opening frame. It was a long introduction to what the left-hander described as “just a strange game.”

“Starting the first inning there, getting some weak contact and then still end up throwing 30-plus pitches when I felt like I had some of my best stuff this year,” Corbin said. “Then, it kind of happened again later.”

Following a scoreless second, Corbin gave up a pair of solo home runs to Austin Hays and Anthony Santander in the third that totaled a Statcast-projected 819 feet. It was Corbin's third straight outing with two homers allowed.

“I didn’t know [about the starters’ earned run streak], but obviously that’s our job,” Corbin said. “We’re trying to go out there and put up as many zeros as we can.”

Corbin exited after four innings with three earned runs allowed on seven hits and one walk and six strikeouts across 83 pitches (63 strikes). It was his second straight abbreviated outing after throwing 3 1/3 frames in his previous start last Thursday vs. Philadelphia. Corbin dropped to 3-10 with a 6.60 ERA.

“Numbers-wise, it’s terrible,” Corbin said. “I feel my stuff was pretty good. I was up to 96 [mph] today. I thought I had some good sliders, good command on my fastball, did get some weak contact. I think, other than those two homers there and a lot of foul balls, which drove the pitch count up, but like I said, I felt like my stuff was pretty good. But maybe it’s not.”

Following the first rain delay, there was an opportunity for the Nats’ relievers, who had been locked in of late, to fend off the Orioles’ bats while their quieted offense looked to get going. In their previous three contests, Washington’s pitching staff had given up only one earned run in 28 innings for a 0.32 ERA.

When play resumed following a 44-minute break, Erasmo Ramírez pitched a scoreless fifth. But after that, Steve Cishek allowed a career-high-tying four earned runs off four hits -- including a double that made Hays the third player to hit for the cycle against the Nats in team history (since 2005) -- and a walk.

“We were watching [Cishek], and a couple pitches he threw 85, 86 mph because he couldn’t get a grip,” Martinez said. “So that’s an indication that it’s getting a little dangerous out there.”

The contest was delayed for a second time after the sixth. An hour and 2 minutes later, it was called because of inclement weather and ruled an official complete game. The Nationals then packed up for a three-game series against the Rangers that begins on Friday in Texas.

“Overall, I like the way we’re pitching, I really do,” Martinez said. “If we continue to do that, we’ve just got to get consistent with our bats. … We’ve got to start knocking some runs in and try to put the pressure on the other team.”