The Razorbacks scored the first 7 points of the fourth quarter to get within 48-46. Vanderbilt went on an 8-3 run to get a 7-point lead before a Poffenbarger free throw and Carly Keats three-pointer shrunk the advantage to 56-53.
Vanderbilt then ended the game with six unanswered points.
Spencer led Arkansas with 19 points and Keats added 13. Poffenbarger left the game early in the third quarter when she fell hard to the ground and hit her left knee on the court. She returned later in the game and had a game-high 12 rebounds in 32 minutes played.
Jordyn Oliver led Vanderbilt with 12 points and Sacha Washington added 11. The Commodores shot 20 of 59 (33.9%) from the floor, 4 of 16 (25%) from three-point range and 18 of 21 (85.7%) from the free-throw line.
The Razorbacks (18-11, 6-8 SEC) got within 56-53 with 4:32 left but were outscored 6-0 over the final stretch. Six combined technical fouls were called, and Arkansas fifth-year guard Makayla Daniels was ejected late in the third quarter on her senior day.
Vanderbilt (20-8, 7-7) led for all but 2:58 of the second half and won a game with plenty of NCAA Tournament implications. The Commodores were among the last four teams in ESPN’s bracket projection entering the contest and the Razorbacks were among the first four out.