The Crimson (7-0) have won six straight road games during the streak, which also includes winning last week's Battle 4 Atlantis tournament in the Bahamas by beating then-No. 22 Florida State in the semifinals and Central Florida for the championship.
Harvard's seven consecutive wins matches the best start to a season by an Ivy League school since Princeton did it to open the 1997-98 campaign.
The Crimson carried a 36-26 advantage into halftime, but the Catamounts went on an 8-0 run to cut the deficit to 39-35 with 13:30 to play. Harvard pushed its lead to 43-39 with 9 minutes left, and Rivard buried a long 3 from the right side, upping the Crimson's advantage to 49-39 with 6:19 remaining.
Four McGlynn led Vermont (4-3) with 15 points.