With the Clarkson crowed in a frenzy, Harvard maintained its composure long enough to even the game.
Farrell collected the puck at center ice, and racing in on the left side, unleashed a blistering slapshot that flew into the net at 13:40.
Clarkson took the lead back, however, on a power play goal late in the period.
At 7:11 of the second period, with Clarkson up 2-1, the Crimson scored a power play goal when junior forward Steve Flomenhoft tipped in a Farrell slaphshot from the blue line.
But Clarkson took the lead for good at 16:52 of the second period when senior Ed Sabo pushed in Ed Henrick's rebound past Roy to put the Knights up, 3-2.
THE NOTEBOOK: Freshman defender Bryan Lonsinger, who filled in for injured sophomore, Derek Maguire last night, will likely miss tonight's game after injuring his right knee 9:48 into the third period.