That topped the 60,342 fans who attended a Vancouver Whitecaps game in 1983.
Helping to boost ticket sales Saturday was an appearance by star Los Angeles midfielder and former England captain David Beckham.
It was the first-year Major League Soccer club's second large crowd of the season after 58,912 attended Montreal's home opener on March 17 against the Chicago Fire.
The Impact are only playing at the Big O to start the season. The team is scheduled to move into a renovated 20,000-seat Saputo Stadium on June 16.