"These are big games," center fielder Jacoby Ellsbury said. "For him to come in with the expectation he has on him, he's been lights-out. He has pitched tremendous."
Tanaka's efficiency during this early stretch of the season has been uncanny. He struck out seven batters without allowing a walk on Tuesday, bringing his total to 35 strikeouts and two walks on the season.
That strikeout total through four career starts is tied for third-most in the Majors over the past 100 years.
"I could be wrong, I'm making an assumption, but I would assume that he's been followed pretty closely over in Japan. I don't think this is really anything new to him," shortstop Derek Jeter said. "He has a great presence on the mound, it doesn't seem like he's fazed by too much. He has a lot of confidence in his ability on top of having a lot of ability. He's fun to play behind, he's been fun to watch."
Tanaka said he could feel the rich tradition and history of Fenway as he took the mound.
"I think I was a little bit pumped up today," Tanaka said through an interpreter. "I know how good their lineup is and how small the stadium is. That is one thing I had in mind."
Improving to 3-0 on the season with a 2.15 ERA after the win, Tanaka has yet to lose a regular-season game since Aug. 19, 2012, with the Rakuten Eagles in Nippon Professional Baseball. He is a staggering 31-0 in that time.
Getting four runs of support from the Yankees' offense after just three innings, Tanaka mowed down Boston hitters in that stretch, facing just one over the minimum.
However, Tanaka fell into a little bit of trouble in the fourth, allowing back-to-back home runs to David Ortiz and Mike Napoli and a double to A.J. Pierzynski. It marked the first time this season Tanaka allowed multiple home runs.
"I think bouncing back after giving up the two home runs and the double. Making an adjustment, getting right back on track and understanding what he needed to do to get people out was most impressive," said manager Joe Girardi.
Never having faced Tanaka before, the Red Sox hitters were fooled early and often.
"He never gave in. His split is one that presents itself in the strike zone and forces guys to commit. With late action, you're going to get some swing and miss and some mis-hits," Red Sox manager John Farrell said. "But the overall walks issued speaks to his strike-zone ability. He forced us to swing the bat early in the count at times to try to get something going. You know what? He pitched a very good game tonight."
While the Yankees know that Tanaka is just four starts into the season, they're thrilled with the way he's thrown the ball and the composure he's shown on the mound.
"I think we'll continue to learn about him all year long. There are going to be firsts," Girardi said. "There have obviously been things we haven't seen him go through yet that he's probably going to go through. We seem to learn something about him every night."