Next step: keep that form over a full game.
Tanaka (1-1) entered with an 11.74 ERA over his first two starts, but he recovered nicely Friday after Matt Carpenter's two-run homer in the first. The Japanese right-hander allowed three runs, five hits and two walks and struck out five.
''Especially from the start of the third inning, I thought his stuff got really sharp,'' New York manager Joe Girardi said.
Chapman allowed a two-out walk to Randal Grichuk and a double to pinch-hitter Jose Martinez before Dexter Fowler - the closer's teammate on the World Series champion Cubs last year - grounded out to second to end it. Chapman got his third save on the season.
Dellin Betances struck out three in a scoreless eighth. New York's relievers haven't allowed an earned run over their last 13 1/3 innings.
New York has won its first four home games to start a season for the first time since 2003.
Girardi has tied Tanaka's early struggles to poor control and difficulties with his split-finger fastball. Tanaka's go-to pitch briefly betrayed him when he mis-located a trio of splitters to Carpenter - two in the dirt, one over the plate - before the Cardinals' No. 3 hitter launched his first homer of the season, a two-run shot off a 95 mph sinker.
Tanaka mostly cruised after that. He threw first-pitch strikes to 13 of his first 16 batters and retired 10 straight before Matt Adams' broken-bat single to start the seventh. A fielder's choice and a walk followed, and then Grichuk ended Tanaka's outing with an RBI double to left.
Tanaka also allowed three runs in the first inning of his previous start against Tampa Bay. Now that he's at least put together one solid outing, he's aiming to improve his first-inning performance - he called the early runs '' a little bit deflating'' through a translator.
Michael Wacha (1-1) struck out eight for struggling St. Louis but allowed two homers and four runs over six innings.
SLOPPY ST. LOUIS
The Cardinals are 3-7 this season and lost this one in part because of a messy defensive miscue. In the fifth, Jacoby Ellsbury was held at third on Chase Headley's double, but second baseman Kolten Wong still relayed the ball home from short right field. Catcher Yadier Molina misplayed the short-hop, and the ball rolled toward the backstop, allowing Ellsbury to score.
Wong's throw wasn't far off target, but it also wasn't necessary with Ellsbury already stopped at third.
''I mean you got Jacoby Ellsbury running on first base, ball's hit you know to the wall, obviously I'm coming up ready to throw,'' Wong said. ''I made a throw and you know, it was an error, so it is what it is.''
Girardi generally avoids using the same reliever three straight days, but said that Chapman is ''a different guy.''
''Now, he will probably lobby to pitch tomorrow,'' Girardi said. ''It will be an absolute no.''
Starlin Castro homered to right-center on Wacha's 96 mph fastball in the first inning. The two-run shot was his second this season, both to the opposite field.
Austin Romine put New York up 3-2 with a solo homer in the second, hours after Girardi remarked the glove-first catcher has ''figured it out a little bit'' at the plate.
Matt Bowman pitched a perfect seventh inning and has 15 consecutive scoreless innings dating to last season. He also pitched 12 scoreless innings in spring training.
St. Louis entered the night with a majors-worst 7.86 bullpen ERA.
Cardinals: LHP Tyler Lyons dominated in his rehab start with Triple-A Memphis on Wednesday, but manager Mike Matheny said he is still building up. Lyons is on the 10-day disabled list with a right knee injury.
Yankees: Greg Bird started at first base for the second straight game after missing four games with a sore right ankle and a stomach ailment. He went 0 for 3 and is 1 for 23 on the season with 11 strikeouts.
Yankees: CC Sabathia (1-0, 1.64) has more walks (six) than strikeouts (five) through two starts but has allowed just two earned runs over two New York victories.
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