After Challengers' lost Ayesha Zafar (0) without any runs on the board, the two denied any further inroads to the opposition bowlers and set up a comfortable win for their side.
For Blasters, spinners Anam Amin and their captain Rameen Shamim picked up a wicket each for 22 and 23 runs respectively.
Earlier, Blasters, after winning the toss and opting to bat, scored 124 for five in 20 overs on the back of Javeria Khan's 67. The opener smashed 10 fours in 63 balls and stitched a 59-run partnership for the second-wicket with Javeria Rauf (27).
Syeda Aroob Shah, Fatima Sana and Nida Dar took a wicket each for Challengers.
Scores in brief: PCB Blasters 124-5, 20 overs; PCB Challengers 125-2, 17.1 overs.