Gloucestershire 140 for 3 (O Price 46, Zafar 37*) beat Middlesex 139 for 9 (Davies 46*, O Price 2-18, Payne 2-21) by seven wickets
Victorious in three of their last four outings, improving Gloucestershire kept alive their hopes of progressing to the knock-out stages, but Middlesex are already down and out, consigned to the foot of the South Group after losing their opening six games.
Just as they did against Surrey on Friday night, Gloucestershire restricted their opponents to a below-par total and then managed the chase in a controlled fashion.
Promoted to open the innings on the back of his record-breaking 19-ball 50 against Essex last week, Ben Charlesworth has yet to spark at the top of the order, and he was stumped off the bowling of Josh de Caires for 12 as Gloucestershire lost their first wicket with 24 on the board in the fourth over.
Also pushed up the order, Hammond made a better fist of things, twice cover driving Blake Cullen to the boundary and then stepping down the track and hitting Thilan Walallawita straight down the ground as the home side advanced their score to 43 for 1 while the fielding restrictions were in place.
Cautious beginnings gave way to adventure on the part of Price, the 21-year-old tucking into spinners de Caires and Walallawita to provide Gloucestershire with crucial momentum. The 21-year-old plundered a brace of fours off de Caires in the sixth over and then repeated the feat against Walallawita in the ninth, Gloucestershire reaching the halfway stage of their innings well-placed at 73 for 1.
Requiring a further 67 runs at 6.70 an over with nine wickets in hand, Gloucestershire were well served by their second-wicket pair, who accumulated in a controlled fashion to lay the foundations for a successful chase. By the time Hammond squirted a catch to extra cover off the bowling of Luke Hollman, the partnership was worth 60, the Cheltenham-born left-hander having contributed 34 of those from 38 balls with four fours, and the rate remained at just over a run a ball.
Within four runs of a maiden T20 50, Price attempted to reach that landmark and win the game with a single blow in the 18th over, only to over-balance and fall to a sharp stumping by Davies. Left to finish things off, Zafar remained unbeaten on 37 from 22 balls, with a six and three fours, while skipper Jack Taylor hit the winning run.
Gloucestershire performed at the top of their game to reduce Surrey to 29 for 4 in the powerplay at Bristol 48 hours earlier, but were unable to emulate that feat on this occasion. They began well enough, Payne having Stephen Eskinazi caught at the wicket in the act of driving recklessly and Joe Cracknell hoisting Danny Lamb to square leg as Middlesex lurched to 20-2 in the third over.
But the home side then blotted their copybook when Holden, still to get off the mark, was put down at point by Matt Taylor off the bowling of Zafar with the score on 26. He and Pieter Malan advanced the score to a respectable 45 for 2 at the end of the powerplay as the visitors sought to make the most of their good fortune.
But Gloucestershire continued to press hard and Price had Malan caught at long-on for a 19-ball 21 and Zafar bowled former team-mate Ryan Higgins for one as Middlesex, struggling to contend with spin from both ends, were reduced to 52-4 in the eighth over.
Fortunate to still be at large and determined to make good his escape, Holden led a Middlesex fightback of sorts, partially rebuilding the innings with a restorative fifth-wicket stand of 24 with de Caires. Gloucestershire were already regretting dropping the left-hander when he hoisted Matt Taylor for the first six of the match, and he went on to add a quartet of fours in a progressive innings that yielded 34 from 22 balls.
Veteran slow left armer Tom Smith eventually put paid to Holden's antics, luring him into a trap that saw him hit straight to Price at deep mid-wicket as Middlesex slipped to 76 for 5 in the eleventh.
A good deal of responsibility resting on their shoulders, de Caires and Davies ran hard between the wickets and scored at slightly better than a run-a-ball in adding 29 for the sixth wicket. But Gloucestershire stuck to their task and de Caires, having made 18 from 20 balls, hoisted Price to substitute fielder Zaman Akhter at long-on and perished going for the big hit with the score on 105, while Luke Hollman was run out for one by Smith's throw from deep backward square as Middlesex slumped to 114 for 7 in the sixteenth.
Worse followed for the visitors, Tom Helm falling cheaply to the returning Payne, who applied concerted pressure at the death, keeping things tight to further frustrate Middlesex.
In danger of running out of partners and forced to take matters into his own hands, Davies batted with real purpose to finish just four runs short of a half century, his 33-ball innings containing 3 fours and a six. Blake Cullen stayed with him long enough to stage a ninth-wicket alliance of 22 in 20 balls, but there was no escaping the strong suspicion that the Londoners had fallen short.