Two minutes into the second half, Jessica Jordan sent a crossing pass in front of the goal to Hensley, who pushed the ball past an isolated Andrews.
Hensley notched the hat trick when she broke free down the left seam and outran the Clear Spring defense in the 68th minute.
"It's good to have a player that can play the ball, get a good take and get a good shot on goal," said Boonsboro coach Kyle Lingg.
Hensley was close to matching her season-high of four goals, but instead was issued a yellow card in the 44th minute. After tipping a Boonsboro shot, Andrews was forced to retreat to keep the ball from reaching the goal. Hensley charged the ball and tried to follow the shot, but collided with Andrews after she had secured the ball.
Andrews stayed on the ground for a few moments, but remained in the game and finished with five saves.
"I didn't try to do it, I was just going after the ball," Hensley said.
Boonsboro (11-3) outshot Clear Spring 12-5 and controlled most of the game defensively. The Blazers (5-10) had four shots in the second half - three turned away by Annie Meyers.
"The defense has been playing really well in the last few games," Lingg said. "They're playing as a unit and keeping teams from getting a lot of shots off."
Trailing 2-0 in the second half, the Blazers had three chances to cut into the Boonsboro lead. In a three-minute span, Sarah Dice had a direct kick from just outside the box go off the crossbar and Meyers came up with two saves.
"It's playoff time and we're going to have to come out with a little more intensity," Lingg said. "It's like a second season and we have to play every game hard."
Boonsboro will have to beat Smithsburg for the second time in 2 1/2 weeks to keep its playoff run alive.