Worcestershire were edged out by six runs when they took on Derbyshire in the second match of their pre-season trip to Abu Dhabi at the main Zayed Stadium.
The county included youngsters George Rhodes and Ed Barnard in their line-up.
Derbyshire totalled 298-9 in their 50 overs after being put into bat by Worcestershire skipper Daryl Mitchell on a green surface.
Worcestershire all-rounder Gareth Andrew, who is back to full fitness after last season's lumar pedicle fracture, picked up three wickets.
There were also two apiece for paceman Charlie Morris and England Under-19 all-rounder Barnard plus one for Chris Russell.
Derbyshire were 90-4 n the 20th over before Chesney Hughes (112) and Alex Hughes (60) added 117 for the fifth wicket.
Worcestershire were given a fine start to their reply by Richard Oliver and Mitchell.
They scored 65 in the initial 10 over mandatory powerplay and extended their partnership to 122 in the 17th over.
Mitchell, who had scored 55 in the win over a UAE X1, was dismissed for 58, bowled by Alex Hughes.
Oliver followed up his century against the UAE X1 by making 63 before he was second out to Alex Hughes with the total 156-2 in the 25th over.
After Alexei Kervezee fell for a first ball duck to Alex Hughes, Tom Kohler-Cadmore and Brett D'Oliveira took the total past the 200 mark in the 34th over, scoring 34 not out and 25 not out respectively.
Wickets started to fall at regular intervals but the result was in the balance when the final over began with 11 required for victory.
Shiv Thakor, signed by Derbyshire from Leicestershire at the end of last season, decided the contest when Russell was trapped lbw.
Andrew tweeted: "Great feeling to be out on the park again with the Worcs CCC lads bowling some bungers and hoppers!"
Worcestershire: Mitchell, Oliver, Kohler-Cadmore, Kervezee, D'Oliveira, Cox, Barnard, Rhodes, Andrew, Morris, Russell.