He'll try to continue doing that against one of his former teams in Thursday's finale of this four-game set as the Yankees go for a third straight win over the Texas Rangers.
New York (52-48) has won both games with McCarthy (1-0, 1.42 ERA) on the mound after acquiring him from Arizona on July 6.
The right-hander earned his first victory in pinstripes Saturday, throwing 71 of 99 pitches for strikes while yielding one run with nine strikeouts in six innings of a 7-1 win over Cincinnati.
"He's got top-of-the-rotation stuff, and we're really glad to have him," catcher Brian McCann said.
McCarthy's strong start for the Yankees has only continued his recent turnaround. He's 3-0 with a 1.78 ERA over his last four starts after going 1-10 with a 5.38 ERA over his first 16.
"It's nice that it's just at least a good first impression," McCarthy told MLB's official website. "Mostly, the way the season's gone, it's just more positive outings, more positive outings, and get back to where I want to be and just build on success. Whether it's here or in Arizona, I just wanted to get back into a successful groove and feel like myself again."
McCarthy is 1-3 with a 4.98 ERA in eight starts against Texas since spending 2007-09 there.
The Yankees, winners of five of six, are having few issues with the Rangers. They've held them to 1 for 12 with runners in scoring position while winning the last two games 2-1, including Wednesday's five-inning rain-shortened matchup.
Brett Gardner owns a .353 career average at home against Texas in the regular season, getting three hits in this series after connecting for a solo shot Wednesday.
The Rangers (40-61), owners of the worst record in baseball, have dropped 18 of 21. During Wednesday's loss, they dealt closer Joakim Soria to Detroit in exchange for minor league pitchers Jake Thompson and Corey Knebel.
Colby Lewis (6-7, 6.37) is getting the ball against the Yankees for the first time since winning the decisive Game 6 in the 2010 AL championship series. The right-hander won both of his outings in that series in Arlington, allowing three runs in 13 2-3 innings.
This will be his first start at the new Yankee Stadium, and his first in the Bronx since 2003.
"I think it's kind of cool to be able to pitch in the old Yankee Stadium and the new Yankee Stadium," Lewis said.
Lewis allowed two runs in five innings of a 4-1 loss at Toronto on Saturday, a dramatic improvement after being tagged for a career-high 13 runs in 2 1-3 innings of a 15-6 defeat to the Los Angeles Angels nine days earlier.
"I have to continue to do what I was doing (Saturday)," Lewis said. "I feel like I was throwing the ball really well. I was locating my offspeed pitches. I need to continue to do that. I could cut back a couple of walks, but other than that, I feel like I'm in a pretty good place with the feel of my pitches and how my body feels."
His latest outing, however, gained notoriety for a bizarre incident with the Blue Jays' Colby Rasmus in the fifth. Lewis took offense to Rasmus bunting for a single against an infield shift with Toronto up 2-0, and he continued to voice his displeasure after the game.
"You're up by two runs with two outs and lay down a bunt," Lewis said. "I don't think that's the way the game should be played. I let him know and that was about it."