Hamilton now leads the best-of-seven Calder Cup playoff series 1-0.
Benoit scored his first goal of the post-season on the power play with just under six minute left to play in the third period. Taking a beautiful cross-ice pass from Mikhail Grabovski, Benoit one-timed a slap shot past MacIntyre.
Ajay Baines scored the other Hamilton goal, while Lee Goren had the lone Manitoba goal.
Carey Price turned aside 23 of 24 shots for his fifth win of the playoffs. MacIntyre played well in net for the Moose, stopping 25 of 27 shots.
Both teams showed little life in the opening period, with the only real scoring chance for either team coming with Manitoba on a two-man advantage when Yannick Tremblay rang a point shot off the post.
The Moose outshot the Bulldogs in first period 8-to-5, but they didn't record their first shot until the 7:25 mark.
The second period saw Hamilton control most of the play, testing MacIntyre with eight shots. Baines' goal at 6:55 was the lone highlight for the Bulldogs. Manitoba also fired eight shots at Price, including a laser from Moose captain Mike Keane that found the iron.
Manitoba thought they had finally beaten Price just over six minutes into the third period as a Brad Moran shot went over the netminder's shoulder. The puck trickled close to the goal line before Baines tucked the puck back under Price.
Hamilton withstood Manitoba's third period pressure and Benoit seemingly iced the game late with his goal. Goren cut the lead to 2-1 with a short-handed marker with 25 seconds left to play, but the Bulldogs held on for the win.
Both teams struggled on the power play combining to go 1-for-13 with the man advantage, which included a lengthy two-man advantage for the Moose, who outshot the Bulldogs 27-24 overall. This series resumes Sunday night at the MTS Centre in Winnipeg.