The South African speedster bowled the fastest ball in women's cricket history earlier this week, but her 132kph delivery thudded into Meg Lanning's pads off line and the Australian went on to score a half-century to help Delhi Capitals go top.
But defending champions Mumbai are now level with them after Ismail turned on the afterburners again.
Unable to dismiss the former Australian captain on Tuesday Ismail returned to Delhi's Arun Jaitley Stadium on Thursday (Friday AEDT) and found herself bowling to the current skipper, Alyssa Healy.
This time the ball was not record-breakingly quick, but at 124kph it was definitely quick enough because it also moved sharply off the wicket. It streaked between Healy's bat and pads, and crashed into middle and leg stumps, knocking the latter out of the ground.
Healy's UP Warriorz team were in the foothills of a run-chase at the time, pursuing Mumbai Indians' 6-160. Healy's exit left them 3-15 off 4.1 overs with a mountain to climb. Despite some powerful hitting by Deepti Sharma, who made a maiden unbeaten WPL fifty, UP never came close, closing on 9-118 to lose by 42 runs.
Mumbai's total, based around Nat Sciver-Brunt's 31-ball 43 and some late hitting from New Zealand's Amelia Kerr (39 off 23 balls), seemed below par.
But then Ismail, who has played for Thunder, Renegades and Hurricanes in the WBBL, steamed in bowling quick, straight and setting the tone.
She bowled her four overs straight through taking Healy's wicket and, by conceding just six runs, putting huge pressure on other batters to score. Healy's three took nine balls, Grace Harris took 15 balls to get off the mark.
Harris then hit two sixes but when she was deceived and bowled by Saika Ishaque (3-27) for a 23-ball 15 Warriorz' last hope went with her. Both Warriorz' wins have come with the Australian allrounder at the crease, guiding them home.
"I though Mumbai executed really well with the ball, to be three-down in that powerplay was not a great way to start," said Healy, who must now lift her team to play Lanning's Delhi on Friday (0100 Saturday AEDT) before finishing against Beth Mooney's bottom-placed Gujarat Giants.
"I think we'll need to win both our last two matches to qualify," added Healy.