Jim Allenby’s unbeaten 89 kept Somerset in NatWest T20 Blast South Group contention as they thrashed Middlesex by nine wickets at Uxbridge.

An opening stand of 118 in 13.2 overs between Allenby and Johann Myburgh, who scored 53 from 45 balls with eight fours, was the platform from which Somerset overhauled Middlesex’s 171 for 7 with 12 balls to spare.

Allenby thumped four sixes and nine fours to put Middlesex’s moderate total into context after John Simpson had hit a Twenty20 career-best 84 not out from 51 balls for the home side, with three sixes and six fours.

But Allenby, Myburgh and Peter Trego, who came in at No 3 to finish 28 not out from 12 balls and finish the match in style by pulling a short ball from Paul Stirling over mid wicket for his second six, made scoring 177 for one in 18 overs look ridiculously easy.

It was Somerset’s fourth win in eight games and Middlesex, now with five losses in a row and six defeats from their eight group matches overall, were brushed aside despite the return of England limited-overs captain Eoin Morgan.

Middlesex spinner Ravi Patel, making his comeback after five weeks out with a broken thumb, said: “It didn’t go to plan and we didn’t really perform as we know we can. It was a hard match in which to come back, but it was really nice to be back playing and I’ve missed the buzz of being with the team.

“John Simpson played brilliantly, though. He’s relished the responsibility of going up the order in the T20 this season and he’s certainly got the technique for the job. He can also hit out well at the death, as he showed tonight. But, overall, we didn’t get enough runs on that pitch.”

Morgan was one of a number of Middlesex batsmen who failed to take advantage of a traditionally high-scoring outground, with its fast outfield and shortish boundaries.

Only Simpson got on top of Somerset’s attack for long, after an initial assault from Stirling, and although he did not take a wicket a key bowler for the visitors was Abdur Rehman. The Pakistan slow left-arm spinner conceded only 19 runs in a four-over spell that did much to slow the Middlesex innings.

Stirling, with 29 from 16 balls, gave the Middlesex’s innings a rollicking start by taking 22 from the second over of the match, bowled by Jamie Overton.

He mis-pulled the young fast bowler over mid on for two runs at the start of the over but then took 6,4,6,4 off the last four balls – the first six a pure pick-up over mid wicket which deposited the ball out of the ground and the second six driven high over cover.

There were also two edged fours in the explosive sequence, over gully and through the vacant slip area, but a partisan crowd of more than 3,000 did not care too much about that.

Stirling’s dismissal, however, edging a cut at Tim Groenewald to the keeper, slowed Middlesex, as 34 for no wicket after two overs became 58 for two at the end of the six-over Powerplay, and it took two successive sixes by John Simpson off leg spinner Max Waller, in the ninth over, to kick-start the scoring rate again.

Morgan fell for just seven in that same over, though, hitting a low Waller full toss to Peter Trego at long on and then, as Simpson did his best to maintain forward momentum, several partners came and went.

James Franklin was caught at long off for 7, Andrew Balbirnie holed out to deep square leg in the 16th over, Ryan Higgins had his middle stump knocked out by Overton as he moved right across his crease in a bid to flick to leg, and Ollie Rayner was bowled for 5 trying to reverse sweep Groenewald in the 19th over.

Simpson, however, took two fours from Overton in a 13th over that cost 13 runs and completed his half-century from 30 balls.

The Middlesex wicketkeeper also provided a final flourish to the innings by droving Alfonso Thomas over long on for his third six from the first ball of the last over and following that up by hitting four twos as 14 came from the over.

It was a spirited effort by Simpson, who has now scored 256 runs from six T20 innings this season at an average of 85.33, but it was never going to be enough once Allenby and Myburgh got into their stride.