Entering yesterday’s game, the Harvard field hockey team (9-6, 4-1 Ivy) had much to be proud of. The Crimson stood tied for first place in the Ivy League and maintained the No. 21 ranking in the NFHCA national coaches’ poll.

But until yesterday’s clash with No. 17 Boston University (11-6, 5-0 America East), it had still failed to do one thing: knock off a ranked opponent.

That ignominious streak and a recent losing slide were reversed with a convincing 3-1 defeat of the Terriers on Jack Berry Field at MIT. Losers of four out of its last six games, Harvard rebounded from a week that included an overtime loss to Boston College and a heartbreaking defeat to Princeton, its Ivy co-leader.

With masterful execution of its penalty corners and a stifling defense, the Crimson took the early advantage and didn’t look back. Led by two goals and an assist from senior midfielder Shelley Maasdorp, Harvard captured the away game, transplanted due to BU’s lack of a home turf.

“Certain teams might have stayed down after what we suffered last week,” captain midfielder Kate Gannon said. “I think it shows a lot about the character of this team that we can come back and win a big regional game like this.”

All three goals came on penalty corners, a familiar friend of the Crimson this year. On this afternoon, the team was characteristically accurate, converting three of its four corner chances into goals.

“Corners have been a strength for us in the latter half of the season,” Gannon said “It’s something we practice, and it’s really tough to defend against when the shots are accurate.”

Less than five minutes into the contest, the Crimson drew first blood. A straight shot for Maasdorp was tipped up in the air, allowing junior midfielder Jen McDavitt to sneak in and punch in the deflection. McDavitt totaled a goal and two assists on the afternoon.

Then, after securing another corner as time expired in the first half, Harvard capitalized on the opportunity to complete the sequence it had initiated, with Maasdorp picking up the goal on assists from McDavitt and Gannon.

The Crimson defense, meanwhile, held the Terriers without a shot for the entire first half. A poised back line waited and anticipated their long passes, then stepped up to intercept them and start the offensive.

“They try to have one big ball into the attacking end,” Gannon said. “We prevented a lot of the things that have been working for them in previous games and stopped up their attack.”

After the break, however, Harvard lacked some of the fire that had paced the squad through the first 35 minutes, permitting BU to get back into the game.

“We’ve had some tough games the last two weeks, and we were a little tentative at times in the second half,” Harvard coach Sue Caples said.

The Terriers ended the shutout with 28:36 left in the game, and the Crimson lead grew tenuous. Harvard slid back into its own half of the field, settling into a strategic struggle the rest of the way.

“We executed the game plan,” Caples said. “It was a very tactical game, and we played smart.”

Then, with only a minute left in the contest, the Crimson launched a swift counter-attack to win itself yet another decisive penalty corner. Maasdorp’s team-leading 15th goal of the season, again assisted by McDavitt and Gannon, iced the win with 29 seconds remaining.

“We had a great first half,” Gannon said. “They came back a little bit in the second half. But to score in the last minute, shows we were playing the whole 70 minutes.”

Harvard responded to adversity and picked up arguably its biggest win of the season.

“This was the most complete game we’ve played all year,” Caples said.

Even with the win, an at-large postseason bid is unlikely, but the Crimson will qualify for the NCAA Tournament if it captures the Ivy League title with victories in its last two games and a Princeton loss.