Somerset 178 for 6 (Myburgh 46, Anderson 39, Trego 32) beat Middlesex 175 for 5 (Holden 84, Bravo 32*) by four wickets
Powerful New Zealand allrounder Corey Anderson bludgeoned Somerset to a convincing four-wicket win over Middlesex at Lord's. Anderson's 39 off 24 balls proved decisive, Middlesex left to rue dropping him when he was on two.
The drop was one of two caught and bowled chances missed by Middlesex as for the third game running their bowling and fielding wasn't able to defend the score they had put on the board. Out of action for not far short of a fortnight, they remain marooned near the foot of the table with one win in four games.
The result was harsh on youngster Max Holden, whose 84 was the backbone of their 175 for 5. Dwayne Bravo also featured strongly for Middlesex with a sparkling cameo and two wickets in as many balls.
Dan Vettori, Middlesex's coach, said: ""I don't think we misread the wicket - we probably misread what we thought was a good total. We obviously struggled through those middle stages, but coming off the field we thought 175 was a pretty good score at Lord's. But Somerset really came at us so aggressively, they took the game to us and won it comfortably in the end.
"With Dawid Malan away, Max had an opportunity to bat and to show a style of play we're really happy with. Middlesex have high hopes for him in all formats and the nature of his innings today in front of a big crowd is a real positive.
"In the scheme of things, you need seven or eight wins to make the quarter-final. That affords you six or seven losses but you don't want to put them away so early. The key is to remain positive because if you don't those losses will keep mounting up. Hampshire tomorrow's probably the most important game of the season for us and it can see us back on track."
Eoin Morgan opted to bat on winning the toss and openers Paul Stirling and Holden produced a bright start with 27 in three overs. But Stirling perished at the hands of Roelof van der Merwe when his paddle to the final ball of the fourth over failed to clear short backward square.
Former England U19s captain Holden continued to attack, hitting successive fours off Craig Overton as Middlesex reached 52 for 1 at the end of the Powerplay.
The boundaries though dried up and Stevie Eskinazi holed out in the deep off Max Waller in search of much-needed acceleration.
Holden completed 50 from 36 balls and eventually found the fence hoisting Waller (2-23) over deep mid-on. However, the spinner gained ample compensation in the same over when castling Morgan.
Holden (84) responded by hitting Craig Overton for the first six of the game and another followed before one swing too many saw him bowled by the excellent Van der Merwe (2-26).
But overseas aces Bravo and debutant Ashton Agar supplied late impetus, the former hitting three sixes in succession as he raced to 32 off just 12 balls.
Agar struck early in the visitors' reply having Steven Davies superbly caught by Stirling, but South African Johann Myburgh took heavy toll of a fit again Steven Finn, hitting him for a six and successive fours.
Agar too was smashed over long on for a maximum, Myburgh drilling the next ball back to the Australian who shelled the difficult chance of a return catch - a huge moment in the game.
Peter Trego, so often the scourge of Middlesex, rubbed salt in the wounds by plundering another maximum from the last delivery of the spinner's over.
Tom Helm brought no respite as he too was pulled into the Allen stand as 50 came up inside five overs.
Bravo's introduction into the attack brought a new twist to the drama as he first uprooted Myburgh's middle stump to end a belligerent innings of 46 from 27 balls, before trapping James Hildreth lbw with his next delivery, leaving Somerset 59 for 3.
Despite the double blow Somerset refused to be becalmed, Trego (32) again sending Agar beyond the ropes, but they were pegged back once more when he missed a short one from Nathan Sowter to be leg before.
The biggest moment came when Sowter dropped a ball driven straight back at him by Anderson, the Kiwi celebrating the second chance by hitting Bravo back over his head for six in the next over and following it with three more off Sowter.
He eventually holed out in the deep off Helm (2-29) who then bowled Tom Abell, but the damage was done and Somerset skipper Lewis Gregory hit the winning boundary with 12 balls to spare.