Brookes and Singh (1-12) did an excellent job for their side in the middle overs, controlling the run-rate with efficiency.
Finch returned with gusto, after an excellent recent display in the Rothesay County Championship match against Hampshire, the quick bowler was bowling with pace and aggression, which was rewarded twice in four balls.
Northants soon found themselves 104-7, as Finch first undid McManus with a textbook yorker, before removing the dangerous Zaib for 17, after a superb piece of fielding in the deep from young star Isaac Mohammed.
The fast-bowler changed ends, but his success on the day was far from over as he helped himself to another wicket in his final over, finishing with figures of 3-28 from his four-overs.
Khurram came back to end Sanderson’s cameo of 27 when he sent his stumps cartwheeling, as the Steelbacks’ clawed their way to 152-9 at the completion of their 20 overs.
The Rapids’ pursuit got off to a far from ideal start, with youngster Isaac Mohammed caught at mid-off in the first over, before D’Oliveira was bowled by Willey in the third over as the away side were pegged back at 3-2.
Kashif Ali and Gareth Roderick came together and showed positive signs, playing with intent, as Kashif drilled Sanderson back over his head for a big six into the sightscreen.
The number-four continued his assault, taking Broad’s first over for 18, as the Rapids ended the powerplay 44-2.
Kashif then stepped up through the gears, as he blasted his way to a second Vitality Blast half-century of the season, reaching the feat in 24 balls and including seven boundaries.
Roderick began to exhibit his shot-variety, timing the ball to the midwicket boundary at ease as Worcestershire reached the halfway stage of their innings, 89-2.
Kashif’s display of clean ball-striking provided the visitors innings with exactly the impetus it needed, as he and Roderick notched their 100 partnership off just 52 balls, with Kashif striking at over 200 for almost the entirety of his knock, as he bettered his highest T20 score to date.
His sublime knock of 88 from just 45 balls was brought to a close when the Rapids number-four mistimed a big shot into the leg-side and was caught on the boundary, 12 runs short of a deserved hundred.
He departed with his side 130-3 after his 127-run partnership with Roderick left Worcestershire needing just 23 to win from the remaining five overs.
Roderick fell four-balls later for a well-tempered 36 off 31 balls, as debutant Henry Cullen joined Ethan Brookes at the crease,