Half-centuries from Benny Howell, Michael Klinger and Ian Cockbain guided Gloucestershire Gladiators to a 29-run victory over the Unicorns in the Yorkshire Bank 40 clash at Bristol.
Gloucestershire skipper Klinger held the top order together with 61 before Howell, with an unbeaten 75, and Cockbain, who raced to 53, underpinned a late assault that lifted Gloucestershire to 260 for seven.
Former Surrey youngster Tom Lancefield, who has played for Gloucestershire's second XI this season, led a spirited run-chase by the Unicorns with 76 from 93 balls.
Yet the visitors eventually finished on 231 for five as Gloucestershire secured a third win to maintain their strong challenge in Group C.
Gloucestershire were made to work much harder for victory than they were in a nine-wicket success against the same opposition at Wormsley earlier in the month.
After Klinger won the toss, Gloucestershire were reduced to 75 for three in the 16th over after Hamish Marshall was caught behind off Glenn Querl, Chris Dent was run out by Aneurin Norman's throw from backward point and Alex Gidman edged to wicketkeeper Tom New off Norman.
A stand of 73 in 14 overs between Klinger and Howell revived the innings, but the home captain was then run out by Luke Beaven's direct hit from backward square-leg.
The Unicorns must have been pleased with their bowling and fielding display up to that point, but Cockbain's arrival in the middle changed the tempo dramatically.
He took two fours and a straight six off the 35th over, bowled by Querl, and brought up a 29-ball half-century with the second of successive sixes over long-on from Warren Lee in the 37th over. Lee gained belated revenge from the next delivery when Cockbain skied a pull into the gloves of wicketkeeper New.
The late boundary barrage continued unabated as Howell and James Fuller added a further 42 before the latter was bowled swinging across the line at Beaven's left-arm spin. Gareth Roderick was subsequently run out off the last ball of the innings.
The Unicorns' run chase was given a great start by Lancefield and New, who put on 118 in largely untroubled fashion.
Former Leicestershire player New had contributed 35 when he clipped Howell to midwicket, where Alex Gidman dived forward to take the catch.
Gloucestershire seized control after that, thanks to tight bowling from Howell and Gidman together with some sharp fielding.
Michael O'Shea was caught at long-on by Fuller off Gidman, then Lancefield's 93-ball innings came to an end when he was run out by Chris Dent's throw from cover.
Garry Park and Scott Elstone put on 43 for the fourth wicket before the latter was bowled by Fuller for 17.
Despite some defiant blows from Park, who made 47 before being caught on the midwicket boundary off Fuller in the last over, Gloucestershire ultimately ran out as comfortable winners.