Matt Wieters drives in 3 runs as Orioles beat Kansas City Royals, 4-3

A 48-minute rain delay on Tuesday night might have cost the Orioles their late-inning lead, but it did nothing to their grit.

Soon after the storms over Camden Yards faded, so did a two-run seventh-inning cushion. But that only set the stage for more late-inning heroics.

Catcher Matt Wieters drove in three runs, including an eighth-inning RBI double that proved to be the difference in a 4-3 win over the upstart Kansas City Royals, rewarding those among the announced 12,921 who remained until the final out.

"This team grinds it out," said winning pitcher Tommy Hunter, who threw 1 1/3 perfect relief innings in a tied game. "This team is fun to watch for everybody. Nobody should ever leave the stadium, I'll tell you that much, under any circumstances."

In their first game since completing an 11-game road trip through Oakland, Seattle and Anaheim with a 7-4 record, the Orioles (20-13) continued to build momentum back at home.

"That was an important road trip for us — any time you go to the West Coast and play that many games in a row," Orioles manager Buck Showalter said. "But the experience that baseball has allowed me to have [is] when you come off something like that there's a tendency kind of [to say] 'OK, we're at home,' and have a little period where you have to get adjusted. It wasn't like we scored a whole bunch of runs. But pitching was the difference tonight, and we caught the baseball [well]."

Wieters, who also drove in two runs in the first inning, plated the go-ahead run in the eighth when he slapped a ball off Royals reliever Luke Hochevar that landed just inside the left-field line to score Adam Jones from second.

Jones drew a leadoff walk to open the inning and then took second base on an errant pickoff throw by Hochevar.

"The leadoff walk is something that is going to get you in trouble just about every time, especially late in the game when they got hitters as productive as Baltimore," Royals manager Ned Yost said. "I thought [Hochevar] pitched the ball well. Wieters did a nice job of just serving it down the left-field line for the game-winner."

Hunter (2-1), who has thrown 12 1/3 scoreless innings over his last eight appearances allowed just one hit. Closer Jim Johnson converted his 33rd straight regular season save (and 12th this season) by retiring the Royals (17-12) in order in the ninth. It was the Orioles' sixth win in 10 one-run games this season.

After play resumed from the rain delay in the top of the eighth, left-handed reliever Brian Matusz — who has dazzled since moving to the bullpen — allowed a game-tying two-run homer to Alex Gordon on a 2-2 fastball. It snapped Matusz's streak of stranding 26 straight inherited runners since becoming a reliever.

"The last [pitch] I wanted to be away," Matusz said. "I wanted it to be a fastball away, and I pulled off it and I left it out over the plate. He's a good hitter. He doesn't miss pitches like that very often. … It was just missed location, not necessarily the wrong pitch. I think it was the right pitch, just needed for it to be away."

Before the delay, lefty Wei-Yin Chen held the Royals to one run, scattering nine hits over 6 1/3 innings and just 80 pitches for his fifth quality start in eight outings this season. He struck out two and walked none.

Chen entered with a 7.59 ERA against Kansas City in two previous starts. In his most recent start against the Royals on Aug. 9, he allowed a career-high seven earned runs over 4 2/3 innings.

On Tuesday, Chen danced around danger. He was aided by three double-play balls, including ones that ended the fifth and sixth innings. Shortstop J.J. Hardy also turned in a spectacular diving play on the edge of the outfield grass and threw out Royals catcher Salvador Perez from his knees by a half step.

"The double plays were a huge part of the game today. I'm so proud of the guys behind me who played really unbelievable, amazing play," Chen said through interpreter Tim Lin. "Of course, Wieters was a big part of the game tonight, too. He just threw down the fingers and he didn't miss. It was definitely a good day for us."

In surging within one game of the American League Central lead heading into the night, the Royals' strength has been their pitching. Their 3.33 team ERA heading into Tuesday was the second best in the AL.

The Orioles were outhit by the Royals — 10-8 — but they jumped on Royals starter Ervin Santana early, plating three quick runs against the right-hander in the bottom of the first.

Four of the first seven Orioles batters reached base against Santana — who entered the night riding a 13-inning scoreless streak — capped by a two-out double by Wieters that rolled to the right-center field wall to give the Orioles a 3-0 lead.

Three consecutive singles by Manny Machado, Nick Markakis and Adam Jones plated the Orioles' first run against Santana, who entered 4-5 with a 5.82 ERA against the Orioles in his career.

The Royals, who came into the night winners of four of their previous five, cut the lead to 3-1 in the top of the third on Alcides Escobar's two-out RBI single to right, which plated former Oriole Miguel Tejada from second.