Boyle (8-12) raced to a quick 15-4 lead as Zach Cooley, starting in place of injured Ian Young, White and Vonckx scored four points each while Blake Jones nailed a trey.
But Garrard (9-11) went on a 10-2 run to close the period, as Dan Leavell scored four points while Spencer Toler, Spencer Crutchfield and Sean Paul Leavell added a bucket each to cut the Boyle lead to 15-12 after one quarter.
Both teams had problems scoring in the second quarter. Boyle was 5-for-23 from the field in the period, while Garrard was only 1-for-10. Boyle closed the period on an 8-2 scoring run as Jones scored six points and Smith Ahnquist added two to give the Rebels a 26-16 halftime advantage.
Boyle, who held a commanding 23-5 rebounding advantage during the second quarter, held a 31-16 rebounding advantage at the half and had 16 offensive rebounds.
"We were out of sync when they went into the 2-3 zone in the first half and never attempted to run our offense," Garrard coach Cecil Combs said. "We came out more patient during the second half after making some halftime adjustments.
"Once we got them to reverse the ball, we got some good looks at the basket. When you are 0-for-13 from 3-point range, you had better find a way to score from the inside."
Garrard connected on seven of 11 shots during the third quarter and got nine points from Sean Paul Leavell, but Vonckx managed to score all 10 points for Boyle in the period and the Rebels led 36-31 entering the fourth quarter.
The Golden Lions trimmed the lead to 42-37 after a Toler basket, but Jones' basket after a nifty assist from Cooley gave Boyle a 44-37 advantage.
Rebels hold off Golden Lions
Garrard went into a full-court press and immediately scored twice on baskets by Crutchfield and Dan Leavell to cut the lead to 44-41 with 52 seconds to play. However, Boyle was able to put the game out of reach when reserve Daniel Potts and Vonckx hit two free throws each and Patrick Horn scored off a rebound.
"This was a good win for us," Moberly said. "We had three guys with double figures in scoring and had five guys with five or more rebounds.
"We're playing well down the stretch and that is what good teams are supposed to do. I'm proud of the way we bounced back from our loss (Tuesday to North Laurel). We did not show a lot of maturity in that game, but we came out tonight and played with a purpose.
"Blake and Derek are two seniors that we have depended on all year, and they did a great job providing leadership tonight. I can't say enough about the play from our bench. We could have wilted under the pressure when Derek and David (White) went out with foul problems, but our subs came in and played well."
Combs was pleased with Garrrard's defense.
"If you hold a team to 50 points or less, you are supposed to win the game," the Garrard coach said. "I would have thought we would have been in good shape. We had plenty of opportunties and missed a ton of shots. We missed assignments, and there was no intensity on the boards in the first half. Boyle is too physical for us not to play with intensity.
"We knew we would have to put them at the free throw line late in the game, and to their credit they stepped up there and hit the shots."
Garrard actually outshot Boyle from the field. The Lions were 18-for-46 (39 percent) compared to Boyle's 19-for-53 (36 percent).
Boyle was led in rebounding by reserve Seth Tamme and Jones, two of the smallest players on the court, with six each. Dan Leavell led the Lions with seven. Boyle committed 11 turnovers compared to Garrard's eight.
BOYLE (8-12) - Patrick Horn 10, Blake Jones 11, Daniel Potts 3, David White 4, Zach Cooley 4, Smith Ahnquist 2, Derek Vonckx 16.
GARRARD (9-11) - Spencer Crutchfield 8, Sean Paul Leavell 13, Jake Cool 2, Dan Leavell 10, Brandon Sebastian 2, Spencer Toler 6.