BALTIMORE -- Bud Norris found a way to work around two lengthy rain delays.
Mat Latos did not.
After rain delayed the start of the game for 23 minutes, another shower halted play in the top of the first inning for 1 hour, 46 minutes.
Norris played catch and walked around during the delay. He returned to throw six shutout innings.
"You want to stay loose, you want to pitch," he said. "It's your day to go."
Latos threw his first pitch nearly 2 1/2 hours after the scheduled starting time. The right-hander gave up four runs in the first inning and a solo homer to Jonathan Schoop in the second to fall behind 5-0.
"It (stunk)," Latos said. "You know, all of your adrenaline comes out of the bullpen. I like to create a tempo in the bullpen how I am going to pitch in the game. ... I felt really good coming out of the pen. Mother Nature must have snuck up on us again. It's the second time this has happened to me in two away games."
Latos (5-4) yielded five runs and a season-high 10 hits over five innings in his first loss since July 27.
Nelson Cruz delivered his career-high 91st RBI in the pivotal first inning with a single. Chris Davis and Caleb Joseph added RBI singles around a run-scoring groundout to send the Orioles to their seventh win in nine games.
Baltimore withstood an eighth-inning grand slam by Jay Bruce to extend its lead in the AL East to a season-high 9 1/2 games.
"You do whatever it takes to stay focused for the game," Cruz said. "I think we do a really good job in those situations."
Norris (12-8) allowed four hits, struck out seven and walked one. He was 0-3 with a 5.11 ERA in his previous seven starts against Cincinnati.
"That was pretty impressive to go out there," Orioles manager Buck Showalter said.
Bruce's third career slam, off Darren O'Day, got the Reds to 5-4.
In the Cincinnati ninth, Ramon Santiago doubled off Zach Britton with one out and took third on an infield hit by Billy Hamilton. Britton then got Todd Frazier to hit into a double play to secure his 32nd save.
The game didn't finally end, however, until after a review of the final play. The replay confirmed that Hamilton got tagged in the baseline before Schoop completed the double play with a throw to first.
"As a baserunner, you absolutely cannot be tagged there," Reds manager Bryan Price said. "It's the only way they are going to turn two in that situation. It's those things you got to learn from."
Cincinnati has dropped 14 of 20 and is 15-28 since the All-Star break.
After the first delay, the first play left three people on the ground. Hamilton hit a liner off Norris' leg, and the ball ricocheted toward first base. Norris dived on it and threw to first, too late, and Hamilton ran into umpire Mike DiMuro. Hamilton recovered from the collision but DiMuro left with an unspecified injury.
Hamilton then stole second, setting a Reds rookie record with 55 for the season, before rain forced another stoppage.
Reds: Cincinnati placed RHP Homer Bailey (elbow) on the 60-day DL, ending his season. Surgery "will be considered as something that would certainly rectify the problem," Price said.
Orioles: SS J.J. Hardy was sidelined with back spasms but intended to play Wednesday. "It's as close to 100 percent as possible," he said. 1B Steve Pearce (abdominal strain) expects to sit out the series.
Reds: Dylan Axelrod (1-1) makes his third start of the season. He has a 1.64 ERA and 15 strikeouts in 11 innings.
Orioles: Miguel Gonzalez (7-7) faces the Reds for the first time. The right-hander is 1-1 in four career interleague starts.