Gloucestershire 242 for 4 (Cockbain 123, Klinger 44) beat Middlesex 172 for 6 (Eskinazi 51, Noema-Barnett 3-18) by 70 runs
Ian Cockbain hit his maiden T20 century and the second highest score ever by a Gloucestershire batsman in the competition as Middlesex were put to the sword in a one-sided Vitality Blast game at Bristol.
Cockbain smashed 123 off 61 balls, including 96 in boundaries, to help his side reach 242 for four, their best ever T20 total at Bristol, and secure a 70-run victory.
Michael Klinger, Kieran Noema-Barnett and Jack Taylor gave valuable support. But it was all about Cockbain, who went in with the total 7 for 1 in the second over and holed out to long-on off the final ball of the innings.
In reply, Middlesex could manage only 172 for 6 as their miserable Vitality Blast campaign continued. Stevie Eskinazi top scored with 51, while medium-pacer Noema-Barnett claimed three for 18 from four overs, his best T20 figures.
Middlesex skipper Dawid Malan, axed by England for the Lord's Test, instead found unhappy memories resurfacing of another Gloucestershire run spree against Middlesex seven years ago. He said: "That was Gloucestershire's second highest T20 total and I remember their best because it was against us and I was captain then too!"
Gloucestershire will be concerned that Klinger did not field because of a back spasm and Graeme van Buuren has also injured a hamstring, but even that did not take the gloss of Cockbain's innings.
"I don't think I have ever struck the ball cleaner," he said, "which is strange because I haven't been hitting the ball that well in the last couple of weeks. It helped that the Middlesex bowlers didn't get it quite right on the night and allowed me to hit to the shorter boundary.
"We know now that we have several batsmen capable of going big in T20. It was my night tonight, but if I don't come off there are a number of others with the ability to score quickly and that is one of the reasons we are doing so well. It would be nice to cement a quarter-final place as soon as possible."
The game had started well for the visitors after they won the toss, with Miles Hammond falling to Tom Barber for 5, miscuing to extra cover.
But that was as good as it got for the Middlesex bowlers, who lacked the guile and variation to break a stand of 99 in 11 overs between Klinger and Cockbain before the Gloucestershire captain was caught at backward point off Ravi Patel. The left-arm spinner escaped the carnage, conceding only 18 from his three overs.
There was too much short and wide stuff from the visiting attack and Cockbain was in just the mood to capitalise, reaching fifty off 29 balls including two sixes.
Six more sixes followed in a brilliant display of clean hitting without giving a chance as Cockbain moved past his previous highest T20 score of 91 not out and then to three figures off 53 deliveries.
Noema-Barnett, with four sixes, and Taylor joined in the fun with some savage striking of their own as former Gloucestershire players James Fuller and James Franklin conceded 58 and 53 respectively from their four overs, while Barber went for 62.
By the time Cockbain perished he had extended his boundary count to 12 fours and eight sixes. Only Klinger, with 126 not out against Essex on the same ground in 2015, has posted a bigger score in T20 cricket for Gloucestershire, whose only bigger total was the 254 for 3 they made, also against Middlesex, at Uxbridge in 2011.
The current Middlesex side lost three wickets in the Powerplay, those of Paul Stirling, Dawid Malan and pinch-hitter Fuller in moving to 61.
Eskinazi then joined Morgan in a stand of 86 in ten overs. There was drama at the end of the 11th over when Graeme van Buuren, on as a substitute fielder for Klinger, lay motionless after diving to prevent an Eskinazi boundary and a stretcher was summoned as he was helped over the rope.
Eskinazi reached fifty off 29 balls, but when he and Morgan both fell in the 16th over, bowled by Noema-Barnett, any lingering doubt about the outcome was erased.