Blackwell and Eric Kroshus each logged a goal and an assist and Dan Ford assisted on both goals, but the Crimson (4-4-6, 3-3-4 ECAC Hockey) could not take advantage of a 27-13 edge in shots on goal. Scott Diebold helped the Engineers (3-16-1, 1-7-1) end a six-game losing streak with 25 saves, and Steve Michalek made 11 stops for Harvard.
The teams began the final period with four skaters aside, and the Engineers holding a 2-1 lead. Blackwell used the extra space to even the score at the 1:34 mark. From the left corner of his defensive zone, Ford moved the puck up the wall to Kroshus. The senior fed Blackwell, who carried all the way down the right side, waited for the RPI defenseman to go down, spun around and scored on his backhand.
Harvard skated to its second straight tie and extended its ECAC Hockey unbeaten streak to four games. The Crimson blocked 23 RPI shots, with Mike Seward notching a game-high four blocks. Alex Killorn led all skaters with five shots.
The Engineers jumped ahead early with two goals 26 seconds apart in the game's sixth minute. The first came when Zach Schroeder deflected in Marty O'Grady's point shot. RPI got the puck deep after the ensuing faceoff and intercepted a Harvard breakout pass at center ice, leading to C.J. Lee's goal.
Kroshus cut the lead in half less than two minutes later, as the Crimson scored on its first power play for the fifth straight game. All five Harvard skaters played a part in the goal. Luke Greiner dug the puck out of the corner and passed to Danny Biega, who in turn sent the puck across the point to Ford. Blackwell redirected Ford's point shot on net. Kroshus collected the rebound in the slot and calmly beat Diebold with a shot to the glove side.
Harvard went to the first intermission trailing, 2-1, despite holding a 12-4 shots advantage. The Crimson blocked nine attempted shots by RPI in the first period.
The Crimson did not surrender an RPI shot on goal in the first 13 minutes of the second period and outshot the Engineers by a 9-1 margin, blocking 10 more Rensselaer attempts.
Harvard pinned the puck deep in the RPI end for much of the period but could not even the score. Killorn had perhaps the Crimson's best chance when he swooped in from the left side six minutes before the intermission, but Diebold saved his close-range backhand shot.
After Blackwell tied the game early in the third, neither team managed to pull ahead as each totaled five third-period shots and Rensselaer killed a late Harvard power play. The Engineers looked set for on odd-man chance with two minutes left, but a backchecking Killorn was there to lift an RPI stick and prevent a shot.
The line of Blackwell, Greiner and David Valek generated some chances on a strong shift early in overtime, but the Engineers had three of the four combined shots in the extra frame.