Worcestershire 124 for 5 (Fell 48*, Mitchell 20) beat Nottinghamshire 121 (Nash 51, Parnell 5-24) by five wickets
A five-wicket haul by Worcestershire all-rounder Wayne Parnell led his team to a five-wicket win against Nottinghamshire, who surrendered their unbeaten record in this season's Royal London Cup.
South African Parnelll, who has signed a three year contract as a Kolpak player with Worcestershire, returned his best List A bowling figures in England of 5 for 24 as the Outlaws were restricted to 121 for 9 in 32 overs at Blackfinch New Road with Paul Coughlin having to retire injured.
Three of Parnell's wickets came in one over with his three previous five-wicket hauls in List A cricket all achieved in his native country, including his career-best 6-51.
But it was a disciplined performance by the entire Worcestershire seam attack which included Pat Brown, the bowling star of last year's Vitality Blast triumph, for the first time in 2019.
Tom Fell followed up his first half-century of the season against Warwickshire at the weekend by hitting an unbeaten 48 as the Rapids triumphed with 24.5 overs to spare.
Victory reinforced Worcestershire's hopes of securing a place in the knockout stages in a competition where they have topped the North Group for the past two years.
Nottinghamshire elected to bat and handed a List A debut to Lyndon James, who replaced Ben Duckett after his England call-up to face Ireland on Friday.
But they never recovered from losing three wickets for 31 runs to the new ball pairing of Charlie Morris and Brown. Former Worcestershire batsman Joe Clarke was undone by a Morris delivery which cut back and James departed for a duck as he tried to whip Brown through mid wicket and was lbw.
Morris collected a second scalp when Jake Libby nicked an away swinger through to ex Notts player Riki Wessels, who was deputising behind the stumps for the ill Ben Cox.
Parnell then took centre stage with his treble wicket maiden just when Chris Nash and Samit Patel appeared to be steadying the Notts innings at 58 for 3. Patel (12) pulled the first delivery to Ross Whiteley at deep square leg and the third and sixth balls beat the defensive pushes of Steven Mullaney (0) and Tom Moores (0) who were both bowled.
Nash offered the only prolonged resistance, striking Worcestershire's stand-in captain Brett D'Oliveira for six over long off.
But Notts' problems heightened as Coughlin (11 not out) drove Parnell to mid off and suffered a hamstring injury completing a single. He had to be stretchered off.
Nash completed an excellent half-century off 66 balls with six boundaries but then pulled the next delivery from Daryl Mitchell straight to Fell at square leg.
Parnell then wrapped up the innings with Matt Carter holing out to mid-wicket and Jake Ball nicking to first slip.
Wessels began as if he intended to finish the game in double quick time against his former county until he was lbw for 18 to Luke Wood.
The paceman, who spent part of last summer on loan at Blackfinch New Road, then bowled Australian Callum Ferguson in the first appearance of his second spell with Worcestershire.
Mitchell (20) holed out to mid off after Patel entered the attack and D'Oliveira (0) was run out in a mix-up with Fell after turning the same bowler on the leg side.
A similar sort of misunderstanding between Fell and George Rhodes saw the latter depart in the same manner for five after failing to beat Mullaney's throw from square leg.
But some typically lusty blows from Whiteley in partnership with Fell saw the Rapids over the finishing line by mid-afternoon.