The Bulldogs dropped their first five-set match of the season at Penn on Saturday evening.
Kathyn Attar matched her season-best with 19 kills and Yale battled to force a fifth set in Philadelphia a night after defeating second-place Princeton. The Bulldogs remain in first, one match ahead of Princeton with four left in the season.
Penn hit .500 in the deciding set without an error to send Yale to its first loss in seven matches.
Attar kept Yale close. After Yale fell behind 13-10, Attar came through on two straight points with kills.
Penn had an answer. Parker Jones delivered a kill to put the Quakers at match point and kept Yale out of reach.
After dropping the second and third sets, the Bulldogs forced a fifth set with big points. Attar knotted the set at 23-23, and gave Yale the lead on the next point.
The teams traded points until Wirth broke a 25-all tie, and an error by the Quakers gave Yale the set.
Kate Swanson finished with a match-high 25 digs for the Bulldogs .
Yale closes out its home next weekend with matches against Harvard and Dartmouth.
Report filed by Ernie Bertothy, Yale Sports Publicity