"The other crews were faster than us," captain Henry Nuzum said after the loss. "It's a pretty simple sport. There were four crews out there who were better than us today."
Rivals Princeton and Penn, the No. 2 and 5 crews, respectively, handed the Crimson its only dual meet losses on the season.
But those losses were alleviated by an early-season win over No. 3 Brown. The Crimson won with a 5:46.0 to the Bears' 5:48.3 on April 10.
Harvard also notched victories over Northeastern, MIT and Navy.
On May 29, the Radcliffe heavyweight crew finished in sixth place at the NCAA Championships on Lake Natoma in Rancho Cordova, Calif.
The Black-and-White finished with a time of 7:02.79, well behind champion Brown's 6:46.89.
Coach Liz O'Leary said after the race that it was an encouraging result.
"I thought it was a really strong performance overall," O'Leary said. "We came out here to race against the best crews in the country, and to consider yourself part of that group is rewarding."
At the Eastern Association of Women's Rowing Colleges (EAWRC) Sprints on May 16, Radcliffe rowed to a fourth-place finish with a time of 6:12.4. Brown rowed to a 6:02.1.
During the dual season, Radcliffe dropped races only to Brown and Princeton. The Princeton race was just a.7-second loss.
The Black-and-White won races against Cornell, MIT, Northeastern, Syracuse, Dartmouth, Boston University, Wisconsin and Yale.
"These seniors are the most intense, tough people I know," junior Anne Browning said. "Their level of intensity and determination cannot be replaced. I'll really miss racing with them."
The Radcliffe lightweights finished the season with a fourth-place finish at the IRA Championships, coinciding with the team's national ranking.
The Black-and-White's 6:48.6 was not enough to challenge first-place Princeton's 6:32.3. The Tigers' closest competitors were Villanova and Virginia, who were sandwiched in between Radcliffe and Princeton.
At Sprints, Radcliffe was third out of four teams with a time of 6:37.5, behind Princeton's 6:31.2 and Virginia's 6:36.3.
The dual meet season was highlighted by two wins over Brown and another over Tufts. The boat was unable to take races over Princeton and Virginia in the early part of the season.