Middlesex 162-6 (16 ovs): Morgan 59, Simpson 26; Groenewald 2-28
Somerset 166-5 (15.5 ovs): Hildreth 63; Helm 2-24, Finn 2-31
Somerset (2 pts) beat Middlesex (0 pts) by five wickets
Middlesex conceded 16 runs in the final over at Taunton to suffer defeat in a T20 Blast game reduced to 16 overs per side.
Eoin Morgan had smashed 59 from 28 balls as the visitors posted a competitive 162-6.
But veteran James Hildreth responded in kind, hitting 63 off 34 balls, to set up a thrilling finale as Corey Anderson and Reoluf van der Merwe held their nerve at the death.
Unhappy at having to play on what he considered a dangerously wet outfield, Middlesex captain Brendan McCullum was further piqued when, having scratched seven from 12 balls, he mistimed a drive off Tim Groenewald and was brilliantly held one-handed by an airborne Peter Trego at mid-off.
Nick Gubbins made 21 before being run out and it was left to England T20 captain Morgan and John Simpson (26) to provide some impetus, with a stand of 66 in five overs.
Morgan launched seven sixes, as many as his team-mates put together, before eventually finding the hands of Craig Overton at long-on.
Ryan Higgins then hit 20 off five balls to ensure Somerset needed to score at 10 an over, which got off to a good start thanks to pinch-hitter Lewis Gregory’s 12-ball 25.
However, at the end of the powerplay, they were 47-3 and were indebted to seasoned campaigner Hildreth’s canny improvisation, as he clubbed a four and two sixes off the 10th over, sent down by slow left-armer Nathan Sowter.
Somerset still required 33 from 21 balls when Hildreth’s fine innings came to an end, Simpson taking a catch behind off the bowling of Tom Helm.
That came down to 13 from six, and Anderson and van der Merwe took on James Franklin to inflict Middlesex’s fourth loss in seven games.