Harvard rallied with a pair of runs in the bottom of the inning, but the Elis responded with two of their own in the top of the sixth to keep a five-run lead.
But the Crimson still didn't give up. Renninger capped his four-hit day with a single to load up the bases in the top of the seventh. McConaghy cracked an RBI single and Durand sacrificed as the Crimson pulled within two, 9-6.
But the gods who had smiled on Decareau in game one paid him back in the nightcap. With two men on, Decareau stepped up to the plate representing the tying run, and struck out as Eli righty Mike Farrell earned his second save of the day.
"It seems the only time we can score is when we're behind," O'Connell said, "and we just can't do it all the time."
The losses put the Crimson in the unenviable situation of needing a two-game sweep against a hot Penn team on its home field this weekend to remain in the race for the EIBL title.
"We're in the situation now where we'll have to win all the rest [to contend for the league title]," Ubert said. "We have no room for air."