Gloucestershire 160 for 6 (Klinger 60, van der Merwe 3-16) beat Somerset 158 for 5 (Gayle 40) by four wickets
Michael Klinger led from the front as Gloucestershire clinched a nail-biting four-wicket NatWest T20 Blast win over Somerset with one ball to spare under the Bristol floodlights.
The skipper hit 60 in a low-scoring contest to guide his side to 160 for six in front of a large partisan crowd. Roelof van der Merwe took three for 16 from four overs to ensure a close contest.
After rain had delayed the start until 7.05pm, Somerset posted 158 for five, Chris Gayle top-scoring with 40. Benny Howell picked up two for 29, while Tom Smith and Kieran Noema-Barnett combined well in mid-innings to restrict the scoring rate.
It didn't look enough, but a see-saw contest ensued before Gareth Roderick hit the penultimate ball from Yasir Arafat for a boundary.
The match began with the unusual sight of Gayle playing out a maiden from Matt Taylor. But soon the West Indian was giving an 11,000 crowd, the biggest ever for a domestic match at the ground, a taste of what they had come to see.
Having taken nine balls to get off the mark, Gayle blasted 6 fours and two big sixes off Liam Norwell and Andrew Tye before skying Noema-Barnett to extra cover where Michael Klinger took an excellent catch in the seventh over.
"It was a fantastic atmosphere and I want to thank all our supporters who turned out to make it such a memorable evening," Klinger said later. "If Chris Gayle had hung around for a few more overs it might have been a different story. When he skied that ball into the lights and I got underneath it I was praying I didn't drop it."
Thanks largely to Gayle, Somerset reached 55 by the end of the six-over powerplay. But from then on their innings lost momentum as Noema-Barnett and left-arm spinner Smith, who took a brilliant caught and bowled to dismiss the dangerous Peter Trego, stemmed the flow of boundaries.
At the halfway stage the visitors were 83 for two. But Jim Allenby (27) fell to a catch at short fine leg, Mahela Jayawardene looked sadly out of touch in making 24 and Johann Myburgh quickly followed him back to the pavilion in the same Howell over.
It took a late assault from Lewis Gregory (23 not out) and Roelof van der Merwe (18 not out) to get Somerset to a competitive score, which still looked below par.
Gloucestershire's reply got off to a disastrous start as Hamish Marshall pushed only half forward to the first ball and was bowled through the gate by Yasir Arafat.
Klinger and Ian Cockbain took the score to 40 in the sixth over before the latter, on 23, carelessly pulled a short ball from Jamie Overton straight to Gregory at deep square.
Chris Dent (22) helped Klinger add 63 before being bowled advancing to hit van der Merwe in the 13th over by which time Gloucestershire required only 56.
Klinger went to his half-century off 36 balls, with 4 fours and a six, offering a reassuring presence throughout. Benny Howell fell cheaply to the excellent van der Merwe, who followed up by having Noema-Barnett caught at long-off in the same over.
Somerset must have rued leaving out leg-spinner Max Waller as their quicker bowlers proved easier to hit. But they kept chipping away and finally got rid of Klinger, bowled by Gregory aiming a big hit after a change of ball.
Gloucestershire required 30 off the last three overs, with four wickets in hand. Arafat and Gregory did their bit and 14 were still needed as Arafat's first delivery of the final over was hit for a straight six by Tye.
That changed everything and Gloucestershire edged home.