ARLINGTON, Texas — — When the Orioles gathered for a workout Thursday at Rangers Ballpark for the start of the unofficial second half of the season, manager Buck Showalter gathered his team under the hot Texas sun for a brief meeting behind second base.
"The look on their faces told me, 'OK, I don't need to do this,'" Showalter said.
Showalter often talks about how this group of Orioles players are easy to trust, so he saw quickly that there was no need to preach the importance of sustaining their level of play down the stretch in search of a second straight playoff berth.
The Orioles began the second half this weekend with their first road sweep of the season, relying on eight strong innings from All-Star right-hander Chris Tillman in a 4-2 win over the Rangers on Sunday.
The Orioles (56-43) have now won five straight and are now a season-high 13 games over .500 — through 99 games last season they were just five games over — as they head to Kansas City, Mo., for a four-game series against the Royals.
Tillman (12-3) recorded the ninth win in his past 10 decisions, holding the Rangers to two runs on six hits over eight innings, striking out seven and walking three. His 12 wins this season match last year's club high by left-hander Wei-Yin Chen.
"I felt good," Tillman said. "There have been multiple starts this year where I felt just like that. I think comes down to execution, being able to execute a pitch in a situation. [Catcher Matt Wieters] did a fantastic job of mixing it up right when we needed it and only when necessary."
The Rangers' Nos. 2-5 hitters were 2-for-14 with four strikeouts against Tillman. As a team, Texas was 3-for-22 with runners in scoring position for the series with 25 runners left on base.
The Orioles have received seven quality starts in the past eight games, with all seven producing wins. Over the three games here in Texas, Orioles starters were 3-0 with a 1.71 ERA.
"He had his fastball really working for him, and really we had all three off-speed pitches working," Wieters said of Tillman. "That makes it fun for a catcher. Knowing I can put down any finger and he can be around the plate with some pretty nasty stuff. He really had everything working, and I could really call any pitch and been comfortable with it."
The Orioles' offense continued its weekend assault on Rangers pitching — outscoring Texas 14-6 in the three-game series — led by Wieters, who was 2-for-4 with an RBI and two runs on the night and was 6-for-12 in the series.
The Orioles are now 16-8 this season against the American League West, and their .667 winning percentage against the division is their second-best since each league went to a three-division format in 1994.
They did their damage in Texas, where they had lost five of their previous six regular-season games entering the series. The Orioles never trailed during the series, had a lead in each game by the second inning and outscored the Rangers 12-0 through the first three innings of the three games here.
The Orioles left Rangers Ballpark — where they ended the Rangers' season last year by winning the AL wild-card game — by sending them to their seventh loss in their past eight games. The Rangers were swept in a series of three or more games for just the second time this season.
Tillman, who improved his career record to 11-1 against the AL West, has been especially dominant on the road, going 7-1 with five quality starts in nine starts away from Camden Yards. He has allowed three or fewer runs in 16 of his past 18 road starts dating to July 4, 2012.
"I think anytime you come into a ballpark like this, a ballclub like this, and get them all, I think that's important," Tillman said. "It's a good start to the second half. Hopefully we can keep it rolling."
The Orioles scored first on Wieters' second-inning single off Texas starter Martin Perez after Chris Davis had led off with a double.
Three batters later, Brian Roberts hit a run-scoring single with the bases loaded to give the Orioles a 2-0 lead.
Back-to-back two-out doubles by Wieters and J.J. Hardy brought in another run in the third, and Manny Machado's fourth-inning single scored Roberts to make it 4-0.
The Rangers (54-44) scored their first run on Ian Kinsler's two-out RBI single to right in the fifth, but Texas ran itself out of the inning when the Orioles initially caught Kinsler between first and second and then snagged Davis Murphy between third and home in an inning-ending rundown that was scored 9-3-4-5-2.
Tillman held the Rangers to just two hits over his last three innings of work, tying his season high with eight innings, which is also the club high set six different times.
He left the game one batter into the ninth after Adrian Beltre's 22nd homer of the season, a solo shot to center field. After Brian Matusz struck out A.J. Pierzynski, he walked pinch hitter Jurickson Profar.
With closer Jim Johnson unavailable after back-to-back outings, right-hander Darren O'Day faced the tying run twice but struck out Murphy swinging for his second save of the season.
"I don't state the obvious to these guys," Showalter said. "That shows a sign of mistrust. We had some things that we've done well that we need to continue to do, and we're off to a decent start, but there's 63 left to play. Just trying to give ourselves the chance to play meaningful games in September."
An earlier version of this story misstated the Orioles' current winning streak. With the sweep of the Texas Rangers, the Orioles have won four straight games. The Sun regrets the error.