Australian batter Harris produced an astonishing display to make light work of Surrey’s run chase after seventh-placed Warwickshire finished on 180-5 at the Oval.
Skipper Bryony Smith got the hosts off to an excellent start in reply by scoring what was the quickest half-century of the season so far when she went to 50 from 23 balls in the eighth over.
But Harris immediately shattered that to equal the all-time Women’s T20 record with six fours and four sixes from 15 deliveries on the way to 50.
It matched her own previous record for the quickest half-century in a Women’s T20 match, equalled only by Marie Kelly in 2022 and Fatima Sana in 2026.
Smith eventually fell for 54, skying one to Mary Taylor off Charis Pavely, but her 78-run partnership with Harris in just 29 balls had done most of the damage to leave Surrey needing another 56 runs with 11 overs to spare.
Harris continued to send the Bears bowling attack to all four corners before she was finally dismissed for 81 from 32 balls with Surrey just seven runs shy of victory, holing out from Millie Taylor to Pavely, who took a fine catch on the boundary.
Jemima Spence was removed for 20 following an excellent catch by Amu Surenkumar at full stretch diving forward, leaving Alice Monaghan to knock off the winning runs in the 15th over to ensure Surrey bagged a bonus point.
But the plaudits belonged to Harris, despite a valiant first-innings effort from the Warwickshire top order, including a 50 for Abbey Freeborn and an unbeaten 45 for Pavely.
