Gloucestershire returned to the top of the Vitality Blast South Group after scrambling to a four-wicket win over Sussex at Hove.
A slow pitch was perfect for the visitors' pace-off attack who set up their fifth win from seven games by restricting Sussex to 127 for eight after Luke Wright had won the toss.
Spinners Rashid Khan and Danny Briggs bowled with predictable accuracy to share four wickets but Gloucestershire, having been briefly displaced as leaders by Somerset earlier in the day, enjoyed the extra pace provided by the rest of the Sussex attack and reached their target with 10 balls to spare.
Sussex never recovered from a poor powerplay when they slumped to 27 for four.
Phil Salt was run out by Michael Klinger's direct-hit from midwicket before David Payne picked up two wickets in seven balls including Wright (16), who hit four boundaries before mis-timing a drive to mid-on.
When Michael Burgess fell for a single to Andrew Tye the Sharks were reeling, but Laurie Evans briefly revived their hopes with 46 from 36 balls.
Evans was just getting into his stride, having taken Kieran Noema-Barnett for a six and two fours in the 13th over, when he holed out to long-on in the 14th off former Sussex slow left-armer Tom Smith.
Sussex did not find the ropes again until Jofra Archer cleared the ropes off the penultimate ball of the innings, the only boundary not scored by either Wright or Evans.
Archer's unbeaten 26 gave Sussex a glimmer of hope but even he was becalmed by an excellent attack with Payne and the experienced Tye outstanding. They were backed up by a tigerish Gloucestershire fielding display.
Sussex needed early wickets to have any chance and Khan struck with his first ball when Klinger (13) edged behind in the fifth over before deceiving Ian Cockbain with a delivery that skidded on in his next over.
When Miles Hammond (35), who hit five fours and a six, was lbw to Danny Briggs trying a switch-hit Gloucestershire had lost three for 18 in 3.2 overs.
Noema-Barnett (16) hit Briggs for two sixes but was bowled off a bottom edge in the same over and when Archer returned to the attack in the 15th over he immediately had Howell taken at point.
Jack Taylor settled Gloucestershire nerves by hitting successive boundaries off Chris Jordan in the 17th over to effectively settle the outcome and although Ryan Higgins (21) holed out to deep cover in the 19th over, the visitors were only three short of their target.
Gareth Roderick drilled the next ball to the long-on rope to seal a deserved victory.
West Indies paceman Jerome Taylor claimed five wickets as Somerset beat Hampshire by 16 runs in a high-scoring Vitality Blast South Group match at Taunton.
The home side posted 197 for seven after losing the toss, recovering from 17 for three thanks to James Hildreth (57), Corey Anderson (32) and late cameos from Lewis Gregory, who smashed 24 off nine balls and Roelof van der Merwe, whose unbeaten 31 came off just 13 deliveries.
Left-arm seamer Chris Wood notched three wickets with his first eight balls at the start of the innings and at one point had figures of four for nine from 2.1 overs. He finished with a career-best T20 return of five for 32.
In reply, Hampshire were given hope by a fifth-wicket stand of 82 in 8.3 overs between James Vince (74 off 45 balls) and Liam Dawson (82 off 41 balls), but eventually fell short as Taylor claimed five for 15 from four overs and Jamie Overton three for 37.
Wood scuppered Somerset's hopes of a good start by sending back Steve Davies for a first-ball duck and Peter Trego in the first over of the match. His second saw Johann Myburgh caught at deep square.
Somerset looked in disarray, but not for the first time this season profited from a long batting line-up. Hildreth and Tom Abell (27) launched the recovery with a stand of 60 in 6.4 overs.
Abell hit Dawson for the first six of the game over midwicket in the ninth over, but perished next ball trying to repeat the shot.
Anderson lofted Dawson for two maximums in the 11th over, but Mujeed Ur Rahman's off-spin proved more difficult to score off as his four overs went for 30.
At the end of the 16th over, which saw Anderson hole out to deep midwicket off Ryan Stevenson, Somerset were 139 for five.
But after Hildreth was caught at fly slip, having reached a 40-ball half-century, Gregory and Van der Merwe launched a savage late assault.
Fidel Edwards went for 24 off the 18th over, with Van der Merwe hitting three fours and Gregory a four and a six to ensure a respectable total.
Overton then grabbed two early Hampshire wickets, dismissing Colin Munro who edged to wicketkeeper Davies and Sam Northeast, well caught by Hildreth running towards the midwicket boundary and narrowly avoiding onrushing team-mate Abell.
Overton also had Vince dropped on 18 by Gregory at mid-on. And when Taylor stuck with successive balls in the sixth over, sending back Rilee Rossouw and Tom Alsop, Hampshire were 37 for four.
Vince timed the ball sweetly to hit seven fours and three sixes, moving to a 32-ball half-century, and Dawson suffered little in comparison, getting to fifty off two fewer deliveries.
But Vince holed out to long-on off Taylor and when Dawson was run out by Max Waller off the first ball of the final over, with 22 still needed, Somerset could relax.