Sean Ervine did the business for Hampshire both with bat and ball
Sean Ervine hit 53 off 26 balls and took four wickets as Hampshire move into serious Twenty20 Cup contention with a second straight win at Uxbridge.
Hampshire piled up 181-6 thanks to the rapid Ervine and Michael Carberry (56), who put on 79 for the third wicket.
But, once young spinner Liam Dawson had taken three of the first four wickets, there was no way back for Middlesex.
Ervine then took a Twenty20 best 4-16 as the holders were bowled out for 125 to confirm a fifth straight defeat.
Middlesex's reign at Twenty20 Cup holders effectively ended at Uxbridge.
Shaun Udal's men cracked under the pressure of an asking rate of more than nine an over, only Billy Godleman offering any sustained resistance, with 34 off 38 balls.
Batting first after winning the toss, Hampshire made a steady start, accelerating gradually toward a late thrust that saw them add 29 in the final two overs with experienced hands Nic Pothas (26 not out) and Dominic Cork (13 not out) at the crease.
Carberry's 56 from 51 balls took him past the 1,000-run milestone in Twenty20 cricket.
But Ervine's quickfire knock, with four fours and as many sixes, was the innings of the night as Hampshire moved to within a point of second-placed Kent in the South Division.
Hampshire manager Giles White told BBC Radio Solent:
"It's a bit tougher away from home but we got a good score and defended it well.
"Generally, it's the openers that have done well for us but tonight it was the middle order. Sean Ervine came to the party, as did Michael Carberry.
"Middlesex were Twenty20 champions last year and were a very good side. Now they look a bit low after losing a few. But they'll bounce back under Shaun Udal. It's all about momentum this game."
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