The Australian left-hander pitched eight innings to lead the Mariners to a 4-1 victory over the Chicago White Sox on Wednesday night.
Rowland-Smith allowed nine hits and struck out two, punctuating his outing with an escape of a seventh-inning jam. The White Sox had runners on first and third with one out, but the bottom of the order failed to deliver as Rowland-Smith (4-3) retired Alex Rios and Jayson Nix.
After the game, Mariners manager Don Wakamatsu paid Rowland-Smith some high praise.
"He looked so polished tonight. I'm awfully proud of him," Wakamatsu said. "This is his eighth quality start since he's been back. He's learning a knack to get deeper and deeper into ballgames. I'm awfully excited about him now and in the future."
Rowland-Smith threw 116 pitches, but it didn't take much for him to convince Wakamatsu to let him go out for the eighth inning, given the struggles in the Mariners bullpen.
"Tonight was good because I felt like I got stronger as the game went on," said Rowland-Smith, whose ERA fall to 3.59. "I was making better pitches. The quality of the pitches was better."
Closer David Aardsma, who last pitched on Sept. 2, worked the ninth for his 35th save.
The White Sox have little margin for error in the AL Central with 16 games to play, falling 6 1/2 games behind first-place Detroit.
Ichiro Suzuki hit the first pitch of the game from Chicago starter Gavin Floyd (11-11) into the gap in left-center for a double. He scored on Jose Lopez's double, one of three the Mariners hit in the first two innings. Seattle made it 3-0 with a sacrifice fly from Ryan Langerhans in the second.
Floyd's early struggles were attributed to a sore left hip, which led manager Ozzie Guillen to pull the right-hander after just three innings and 42 pitches in his shortest outing of the year. Guillen noted Floyd would probably miss his next turn in the rotation.
"Hopefully we can skip him one time and give him a little more rest," Guillen said. "And hopefully he will get better for whatever we got left."
When the game ended, Carp was given a beer shower and had an ice cream pie shoved in his face by a couple of the veterans. A Mariners official was able to track down the ball, and it was handed to him by a smiling Ken Griffey Jr. When Carp looked at the ball, he saw the butchered handwriting that read: "Congradulashun Mike Karp."
Griffey then tossed Carp the real ball and later autographed it for him.
"I grew up as a kid wanting to hit a home run in a big league ballpark," Carp said. "Finally got it out of the way."
The White Sox, who are near the bottom of the American League in team hitting with a .260 average, scored in the eighth on Gordon Beckham's one-out homer to left.
Mariners SS Jack Wilson said after the game it would be a "10 to 15" day situation with his bruised right heel. ... Mariners utilityman Bill Hall was not in the lineup one day after experiencing cramps in his right quad. ... The Mariners said they will monitor RHP Ian Snell to see if he makes his next start as he recovers from a jammed wrist.