Warren senior Alyssa Phillips didn’t smile the entire night.

Frankly, she wasn’t feeling that well when her Blue Devils invaded Mundelein for the North Suburban Lake Division matchup.

Of course, that didn’t stop her from doing her job on Wednesday night. This 12th-grader finished 1 rebound (9) short of a double double (12 points) and added 3 blocks. Warren’s defense held the home-standing Mustangs to single-digit scoring in all four quarters and posted a 40-23 decision.

“Mundelein is a very good shooting team,’’ Phillips said. “But our defense was playing great tonight.”

Great defense or a tough shooting night for the home team? Mundelein (2-6, 2-1) scored 3 field goals in the first quarter and trailed just 13-9 heading into the second quarter. In the next three quarters, the Mustangs

added only three more field goals.

“Our team has improved game by game,’’ said Warren coach John Stanczykiewicz. “These girls are working really hard. And our defense has been really good the last three or four games.”

After Mundelein’s Maggie Mahar drilled a 3-pointer with 22 seconds to play in the first quarter, Warren (4-3, 2-0) went on a 12-2 run and took a 23-13 lead to halftime.

Mundelein junior Lauren Rouse, scored her team’s first bucket of the night on a breakaway. She blamed her team’s offense for the loss.

“We weren’t communicating as much as we should have,’’ Rouse said. “We weren’t attacking the basket.”

Mundelein’s Natalie Busscher (5 points) scored the game’s first basket after intermission and Mundelein was down just 23-15 with seven minutes to play in the third quarter. However, the Mustangs didn’t score another field goal until the final minute of the game when senior Kiana Suhling drilled a 10-footer.

Stanczykiewicz and his coaching staff did not take the Mustangs lightly heading into this contest.

“This was our most complete effort of the season,’’ he said. “Mundelein plays very well at home and they challenge everybody. Busscher and Mahar are their best offensive players and we wanted to limit their looks.”

Both teams struggled offensively in the second half. Warren had only 2 field goals in the third quarter and those baskets by Phillips and Rachel Brown came early in the third quarter. Warren senior Jamie Stirling had all of her 5 points in the fourth quarter.

Phillips paced the Devils with 12 points.

“Alyssa just goes and goes,’’ Stanczykiewicz said. “She’s long and athletic. She’s tough and she’s learning how be a leader of this team.”

Junior guard Kristen O’Brien had a solid game for Warren with 8 points and 8 rebounds. Warren clearly dominated on the boards with 30 rebounds to Mundelein’s 10. While Warren shot a solid 52 percent for the game from the floor, the Mustangs were struggling at 16.7 percent.

Becca Woit led Mundelein with 6 points. Mahar and and Rouse added 4 points each. Cassie Christie had 5 points and 4 assists for Warren.