Wilson Ramos waits for the throw as Baltimore's Jonathan Schoop scores in the third inning of the Orioles’ 8-1 win Tuesday night. (John McDonnell/The Washington Post)

There are nights, even for clubs as good as the Washington Nationals, when very little goes right. When the starting pitcher stumbles, and a defensive gaffe exacerbates his difficulties. When baserunning blunders cripple rallies, luckless situational hitting sabotages others and three replay challenges don’t go your way.

It all happened for the Nationals on Tuesday night in an 8-1 loss to the Baltimore Orioles at Camden Yards. Rookie starter Reynaldo Lopez allowed six runs, four earned, over 22/3 innings to put the Nationals’ fatigued bullpen in a precarious situation. Second baseman Daniel Murphy’s fielding error with two outs in the third inning didn’t help, costing the Nationals two runs and expediting Lopez’s exit. Trea Turner was caught stealing twice after replay reviews in the first three innings, and Clint Robinson ran into an out to stifle a potential rally in the seventh.

The result was the third straight defeat for the Nationals (73-52), yet they still hold an eight-game lead in the National League East because the Miami Marlins lost. The Orioles (69-56) maintained their hold on an AL wild card spot on the back of right-hander Kevin Gausman, who tossed six scoreless innings.

Lopez mowed through the Atlanta Braves in his previous two outings. He logged seven innings in each start and accumulated a career-high 11 strikeouts last Thursday at Turner Field. He quickly found out the feast-or-famine Orioles offense — with a designated hitter at its disposal — resides at another level.

In his fifth career major league start, the 22-year-old Lopez allowed runs in each of the three frames he started, the total increasing by one with each frame. In the first, Mark Trumbo smacked a two-out RBI single to left field to snap a peculiar streak: His previous seven hits had been home runs. In the second, Matt Wieters doubled to score a run and Adam Jones plated another with a two-out infield single.

“He was facing some veteran hitters that can hit,” Nationals Manager Dusty Baker said. “He could have put them away. He’d get two strikes, but we knew they were a very good offensive team. He was facing some veteran hitters that knew what they were doing.”

In the third, Lopez was poised to maneuver out of a jam having surrendered just one run, but with two outs and the bases loaded, Murphy was unable to field a routine groundball off Hardy’s bat, the ball bouncing off his glove into right field. Two runs scored on the gaffe to afford Baltimore a 6-1 lead and conclude Lopez’s night after 82 pitches and eight outs.

“If I make that play right there, he gets a chance to go another inning, maybe settle into the ballgame,” Murphy said. “Unfortunately, I didn’t give him that chance tonight.”

The short outing nearly spelled disaster for the Nationals’ bullpen, but Matt Belisle softened the blow by tossing three scoreless innings for his longest outing since 2011. Baker called Belisle’s effort “a lifesaver.”

Turner led Monday’s game off with a walk and immediately stole second base for his 14th steal in 35 games. On Tuesday, he attempted to replicate the feat off Gausman, who had allowed one stolen base in 22 starts, and Wieters, who had thrown out 37 percent of base stealers, twice in the first three innings. Both times Turner was initially ruled safe. Both times the league’s replay center in New York overturned the call after seeing Orioles second baseman Jonathan Schoop reel in an inaccurate throw from Wieters and apply a tag to Turner’s lower body.

“I just wish he would have made good throws right over the bag I think I have a better chance that way,” Turner said.

Turner has been caught stealing three times in the majors this season. In each case, he was originally called safe before the ruling was challenged and overturned.

The replay system thwarted the Nationals a third time in the third inning. Following Lopez’s exit, Belisle got Jones to hit a groundball to Danny Espinosa and was called out at first. But the Orioles challenged again and, following a 58-second intermission, won another challenge to extend the frame, though Belisle struck out the next batter, Steve Pearce, to limit the damage to three runs.

“I’m kind of new this year to replay, but it’s tough to lose three of them,” Baker said. “I don’t think anybody’s ever lost three of them. To me, it doesn’t make the umpires look very good.”

It took the Nationals until the seventh inning, after Gausman was removed, to get on the scoreboard and even that effort included a blunder. After Ryan Zimmerman and Robinson singled to begin the inning against right-hander Vance Worley, Espinosa laced a single to right field for the Nationals. Zimmerman easily scored from second. Robinson, however, was thrown out trying to go from first to third with room to spare for the inning’s first out.

Turner then singled to post the first four-hit game of his career, but that was the final of Washington’s 10 hits. The threat was extinguished when Jayson Werth grounded into an inning-ending 5-4-3 double play initiated by a twirling whip from Manny Machado to second base.

“We had plenty of hits,” Baker said. “We just couldn’t get that one hit.”

The dud completed the Nationals’ exhausting nine-game road trip. Now they head home, 40 miles down 295, to host the Orioles the next two nights at Nationals Park.