Eric Hirsch and Ian Brink each scored 11 points for the Mounties (2-1), who trailed, 27-18, at half-time.
Benzinger had six points and seven boards in the pivotal third quarter, in which Mount Greylock outrebounded the Blue Devils (2-4) by a margin of 10-2.
“We came in at half-time, and we were like, 'Wow, we really need to get back into this,' “ Benzinger said. “It was coach really stressing inside-out basketball. It was nice to see that coach had a lot of trust in me.
“Everyone was involved in the game. The guards did a great job – Eric [Hirsch], Jack [Thistle], Taylor [Carlough] – moving the ball around.”
Mounties coach Bob Thistle agreed that while Benzinger had the big numbers, it was a big team effort that gave Mount Greylock its second straight win.
"I'm proud of [Benzinger], and I'm proud of all the guys," Mount Greylock coach Bob Thistle said.
"In the second half, we just pounded the ball inside, and Jake responded. He's growing up, literally, in front of our eyes as a person and a basketball player."
The junior center was a reserve last year on a senior-laden Mounties team that went to the quarter-finals of the Western Massachusetts Division 3 tournament.
Benzinger starts this year and started dominating Monday night with a couple of putbacks in the third quarter to help get Mount Greylock within three, 35-32, with 1 minute, 12 seconds left in the period.
The Mounties closed within one when Robby Buffis beat the buzzer for a 3-pointer off a feed from Hirsch to make it 36-35.
The teams traded leads to open the fourth quarter, but the visitors went ahead for good when Benzinger was hacked in the post and converted both foul shots to make it 43-41 midway through the period.
On the Mounties' next trip, Benzinger took an entry pass from Brink and scored to make it a four-point lead.
“It's hard to make that entry pass,” Bob Thistle said. “You think, you've got a guy who's 6-7, and even an old guy like me can do it. But it's hard because the defense gets in the way, and in particular Drury plays great defense.
“That really comes from coach (Jack) Racette. Coach Racette has kids who play as hard as anyone in the league. We know coming to Drury is one of our biggest challenges every year.”
Cole Jackson had a big transition basket to get the lead to six, 49-43, and Mount Greylock went 5-for-eight from the line down the stretch to put the game away.
Justin Girard scored 14, and Alex Heck added 13 for Drury.
The Blue Devils used a 10-5 run midway through the second quarter to get some separation in a back-and-forth first half. Girard opened the run with a putback and closed it with a jumper from the left wing to make it 22-16.
Drury then finished with the last five points of the half – three on a conventional three-point play by Heck with one second left on the clock.
The Blue Devils travel to face Hampden Charter on Thursday.
Mount Greylock visits Wahconah on Friday.