"To see James come up like that and get that big hit was huge."
LaManna's ground-ball single down the right-field line gave St. Francis, which tied for third in the competitive Mission League last season, a 6-3 advantage.
After Canyon tied the game at 3 in its half of the fifth, the Golden Knights responded quickly with its own big half of the inning.
With runners on second and third and no outs, Tei Vanderford chopped a single into left to score P.J. Dezotell, who opened with a walk and moved to second on a double by David Olmedo-Barrera.
Canyon then got two quick outs before LaManna came through with a single that scored Olmedo-Barrera and Vanderford.
"I started off ahead in the count and then it went full," LaManna said. "I just tried to go up there and put the ball in play.
"I kept my hands inside and I got jammed a little. I had a feeling the ball would get through because it had side spin on it. Two-out hits keeps the other team out there longer and it can deflate them."
St. Francis scored three runs in the third to grab a 3-0 lead.
With Andrew Gatti and Cole Ramseyer on base with one out, Dezotell singled to score Gatti and give the Golden Knights a 1-0 lead. Olmedo-Barrera then singled to center field to drive Ramseyer home.
On the play, the Canyon center fielder bobbled the ball, allowing Dezotell to score and make it 3-0.
The Cowboys got a two-run single with two outs in the fourth by Mark Poetker to trim the deficit to 3-2. Jason McKenna hit into a fielder's choice to knot the game at 3 in the fifth.
St. Francis starting pitcher Danny Monarrez went five innings to pick up the victory.
The right-hander allowed four hits before giving way to reliever Jesse Torrero, who pitched two scoreless innings.
St. Francis will next face host Montclair Prep at 5 p.m. Friday in another league contest.