Peter Trego smashed 81 to help Somerset ease past Middlesex by six wickets in the YB40 at Taunton.
The hosts won the toss and asked their visitors to bat but Chris Rogers (29) and Dawid Malan (49) quickly set about building a solid opening partnership.
Their stand of 73 for the first wicket allowed star man Joe Denly to stroll out to the middle with the score on 98-2 and the England international anchored the rest of the innings with a carefully-crafted 60.
He found little support after Neil Dexter (37) had departed, though, as Steven Kirby reeled off three wickets in quick succession to end with 4-52 and restrict Middlesex to 252-9 from their 40 overs.
Trego and Marcus Trescothick began the chase quickly with the latter hammering 28 before departing to Gareth Berg, and that only brought Arul Suppiah to the crease.
Suppiah, whose 60 took just 53 balls, played the aggressor to Trego's patient approach, and the pair put on 110 before Tom Smith struck to prevent the opener from scoring a century.
As a result, it was left to James Hildreth (37no) and Jos Buttler (23no) to ensure Somerset cruised to victory with over four overs to spare via some cavalier hitting.