Giagunto's three-touchdown performance - two on the ground, one in the air - capped a near-flawless high school career. He went 27-1 and was the starter for three of St. Joseph's four consecutive titles.
"This is crazy," Giagunto said. "I didn't expect to come in here and win four state championships. It's insane. I'm lucky enough for this to happen to me."
He had plenty of help.
Miles Pease rushed for 198 yards on 12 carries, including an 80-yard touchdown. He also caught the half-ending touchdown pass that put the Wildcats up by 29-0.
"The way Coach is," Pease said, "there's no kicking a field goal or anything. If we're down in the red zone, we're going for it."
That's the kind of confidence you'd expect from a program as dominant as the top-seeded Wildcats (10-1) have been. They've beaten St. Mary by a cumulative score of 127-0 in the last three title games and have never lost to the Gaels.
St. Joseph, which also won a Cape-Atlantic title this season, has won 15 championships since the creation of the non-public state playoffs in 1993.
"It's just a great moment," Giagunto said. "Every one of our seniors, we're like a family out there. We're just brothers."
St. Mary, the second seed, entered the contest averaging 43 points. Jonathan Diaz had averaged more 9 yards per carry, but the Wildcats defense held him to 17 yards on 10 first-half carries and 84 yards for the game.
Doug Kramer and Ray Lucas intercepted passes for St. Joseph, with Lucas returning his to the 1-yard line to set up a Cody Sampson touchdown run.
The play was part of a 22-point second quarter for the Wildcats.
St. Mary (Rutherford) 0000-0
St. Joseph 72270-36
SJ: Anthony Giagunto 8 run (Jonathan Ryker kick)
SJ: Cody Sampson 1 run (Ryker kick)
SJ: Giagunto 15 run (Cody Sampson pass from Ricardo Quirindongo)
SJ: Miles Pease 18 pass from Giagunto (Ryker kick)
SJ: Pease 80 run (Ryker kick)
Contact Tim McManus at email@example.com or follow on Twitter @ByTimMcManus.