The score gave the Crimson a 6-3 advantage and, more important, took care of all of the Cats' remaining lives in a single blow.
Fusco's evening pushed him further up in the Harvard record book. The junior now has at least a point in 22 consecutive games, just two shy of the Crimson record held by Cleary's brother, Bob.
With 62 points this year, Fusco is tied (with Joe Cavanagh '71) for the fifth best season ever by a player in a Harvard sweater.
For his career, Fusco now has 153 points in his two-plus seasons and trails only Cavanagh, George Hughes '79 and Bob Cleary '58.
The third period also belonged to Harvard, but not its star player, as Greg Chalmers and Brian Busconi added tallies for the second line, and Smith completed his hat trick.
The second line tallies marked the return of Chalmers from a four-game absence because of a separated shoulder.
The junior's poise at center showed all evening.
With Chalmers back in the line-up, the Crimson should have a better shot at RPI tonight.
The Engineers have now won 22 straight games and are ranked second in the nation.
"I wish they were number one," Fusco said. "They're supposed to heat us at homer. We're got nothing to lose.
Nonetheless, playing the league's worst and best on consecutive nights is a trying experience.
It's bad for preparation." Follows said. "You don't get prepared enough for Vermont: but you're overprepared for RPS
"It's a completely different game."
THE NOTEBOOK: Steve Armstrong and Smith had the the Crimson's first period scores...The RPI game is scheduled to begin at 7:30 p.m. at Houston Field House in Troy....MacDonald did not improve on his freshman-record 17 goals...The Crimson can clinch home ice in the quarter-finals of the playoffs for certain with a victory or a Yale loss...Captain Brad Kwong enjoyed his first two-point night of the season with a pair of assists...Chalmers had three points, all goals.