Worcestershire 208 for 8 (Clarke 60, Whiteley 42, Santner 35, Ball 3-34) beat Nottinghamshire 195 (Hales 63, Wessels 49, Hastings 3-31) by 13 runs
Whiteley, who hit six sixes in an over against Yorkshire on Sunday, cleared the ropes on five occasions in making 42 from just 16 balls.
Three came in one over from Harry Gurney which went for 24. Gurney finished with an analysis of none for 57, the most expensive in the county’s T20 history.
His assault stunned Notts, one of the favourites to take the trophy, and underlined the call from his director of cricket Steve Rhodes for England to take him seriously as a candidate for their Twenty20 side.
The loss was the first sustained at home by the Outlaws since May last year, a run of seven wins and two abandonments, which leaves them on six points from as many matches in this campaign, whilst the Rapids’ win lifts them up to three points.
The home side had been set to score 209 for their fourth consecutive win but found themselves pegged back after an aggressive start and could only post 195 for 5.
Riki Wessels made 49 and Alex Hales scored 44 in the chase but John Hastings proved to be an effective matchwinner for the Rapids, taking 3 for 31.
Earlier, 60 from Joe Clarke and a punishing sixth wicket partnership of 60 in just 4.2 overs helped push the Rapids up to 208 for 8, after being asked to bat first.
Clarke scored his runs from only 27 deliveries and hit seven fours and three sixes to get the visitors off to a flying start, which took them past 50 inside just four overs. Clarke took 28 off a single over from Luke Wood.
After Notts had fought back strongly, Whiteley and Mitchell Santner took it away from them again with some destructive hitting.
Santner also showed his big-hitting prowess with three maximums of his own in making 35 from 20 balls.
Santner clubbed one of his rope-clearing blows off countryman Ish Sodhi, who took 2 for 41, including the prized scalp of Whiteley, who skewed the leg-spinner to point.
Jake Ball had earlier removed Clarke and then added some lustre to his final figures of 3 for 34 by removing both Santner and Joe Leach as the innings drew towards a close.
Notts had never chased down a target as large as 208 before but enjoyed an explosive Powerplay to set them on track, rattling up 76 without loss. Hales scored 50 of them, reaching the landmark in just 22 balls, with 12 fours – seven of them coming from eight consecutive deliveries bowled at him by Jack Shantry.
With the game moving decisively away from them they were given a lifeline when Hales went after Brett D’Oliveira but failed to clear Ed Barnard on the deep midwicket fence, with the score on 92.
When Brendan Taylor found 18-year old debutant Pat Brown on the midwicket fence, off Daryl Mitchell for 25, Notts still needed 80 from 46 balls.
Outlaws captain Dan Christian made only two, hoisting fellow-Australian Hastings down to Clarke at long leg. The required run-rate rose to more than over 13, with 66 needed from the last five overs and home chances dipped further as Samit Patel became Hastings’ second victim, pulling to midwicket for 10.
On 44 Wessels reached 4,000 runs in T20 cricket but he perished shortly afterwards and despite Tom Moores and Steven Mullaney throwing the bat in the closing overs the damage had already been done.