Antonio Coleman and Thomson tried to rally against Westside, but the deficit was too much to overcome.
Coleman and Ronkeem Sallywhite combined for 19 points in the final quarter, but the Bulldogs' rally fell short in a 69-63 loss Tuesday evening at Westside.
Westside's Ivory Drummer, who came off the bench, scored 12 of his 17 points in the third quarter to push the Patriots' lead to 54-39, only to see Thomson rally. The Bulldogs got to within five when Sallywhite scored on a layup.
Coleman also hit two 3-pointers in the fourth, including one at the buzzer.
Sallywhite led Thomson with 17 points while Coleman added 11 points -- 10 in the fourth.
Westside's Ronald Campbell hit a trio of 3-pointers to finish with 13 points.
Westside, which won by 10 in the previous meeting, came out firing in to open the game.
Frank Booker made three of Westside's four 3-pointers in the first quarter, with the last coming in the corner to hand the Patriots a 15-3 lead.
Thomson had the early edge underneath, however. Jon Atkins scored all 12 of his points in the first half, scoring eight of the Bulldogs' 10 points at one stretch.
Thomson took a one-point lead at the half, but Westside controlled the third quarter and Booker made his last four foul shots. Booker led all scorers with 26 points and got nine of his last 11 points at the free-throw line.
In the girls game, Westside held the Lady Bulldogs scoreless for about six minutes to start the second quarter on its way to beating Thomson 48-29.
After Brittany Reid hit two free throws for Thomson, Westside went on a 12-2 run to go up 16-6.
Though the Lady Patriots (10-8) struggled with turnovers, their defense helped them take the 19-9 halftime lead.
Guard Jewel Sturgis came through with a handful of blocks -- even making two on one Bulldog possession -- and added eight points.
Jahmia Bradley and Azia Gibson scored a combined 14 points in each half, and Westside attempted 11 more free throws in the opening half.
Thomson connected on three 3-point attempts from three different players in the third quarter to cut the deficit to eight, but Westside quickly regained a double-digit advantage.
Nekia McNair finished with a team-best nine points for Thomson.