Middlesex defeated Worcestershire by 32 runs
Worcestershire's bid to cause ripples at the top of the National League was scuppered as they slumped to a third consecutive one-day defeat.
Despite a fourth successive limited-over half-century for South African all-rounder Zander De Bruyn, plus 40 from skipper Vikram Solanki, the Worcestershire batting failed again.
However, the home side were always up against a topheavy Middlesex score, fuelled chiefly by a fierce attack on Gareth Batty by New Zealand Test all-rounder Scott Styris.
The England off-spinner was made to wish he hadn't been given permission to play on what should have been the final day of the First Test against Bangladesh, being hammered out of the attack as Styris struck him for four big sixes.
Styris's 80 in 83 balls, well supported by former England batsman Ed Smith's 93, essentially proved the difference between the two sides as Worcestershire suffered a second National League defeat inside a month to the men from Lord's - and their third in five league games this season.
Worcestershire, hoping to steady the ship ahead of the unsettling imminent departure of coach Tom Moody, had good reason to think they might topple the early-season Division One leaders.
Inside two overs, Middlesex slumped from 37 without loss to 38 for three, the collapse triggered by two wickets in successive balls from Chaminda Vaas.
Jamie Pipe's stunning catch to remove Paul Weekes started the rot, then Vaas struck again next ball when he persuaded Owais Shah to dolly up a return catch.
Kabir Ali got in on the act in the next over when he had Ed Joyce lbw but the leaders got things back on course in spectacular style, thanks to a stand of 140 in 27 overs between Smith and Styris.
It might have been even more, but Styris went in contentious circumstances. He clearly thought he had dispatched a powerful straight drive into the ground and was therefore caught off a 'bump' ball when he returned a catch to De Bruyn. Sadly for him, umpire Vanburn Holder did not agree.
The New Zealander had been particularly punishing on Batty, one of his four sixes sailing straight out of the ground and into New Road. A rare achievement.
In fact, Styris was responsible for 36 of the 41 runs to come from Batty's six overs; not a happy return for the England man, who was still enjoying a quiet but successful first Test appearance in this country just two days earlier.
Despite not being given a bowl at Lord's, he is expected to keep his place when the team is announced today for Friday's second Test.
A winter signing from Kent, Smith hit his first halfcentury in this competition for Middlesex. It was more measured by comparison to Styris's stormy progress, his 93 having taken 122 balls.
But there was still time for a little cameo knock from Irsan Pathan, who went 4-6-4-out to complete a lively 15 in just six balls before the Middlesex innings ended on 224 for seven.
Worcestershire initially looked to be making a good fist of their reply but Warwickshire old boy Mel Betts struck a double blow by removing Stephen Moore, then snaring the key wicket of Graeme Hick, caught at the wicket while cutting.
Then came the big turning point as Solanki and De Bruyn were both nearly run out in a mid-pitch misunderstanding. The Middlesex fielders looked particularly aghast at umpire Holder's decision to give De Bruyn not out as he struggled to make his ground.
But Holder, a Worcestershire favourite in his playing days, made amends just a ball later, giving the luckless Solanki out lbw to a delivery which looked as if it might have bounced over the top of the stumps.
Despite some typical scurrying from former skipper Ben Smith, a couple of flowing off-drives from Batty until he was run out by DeBruyn, and the South African's latest 50, Solanki's departure proved crucial.
Two of the Worcestershire captain's dismissals in this run of three successive oneday defeats have been controversial and the fact that the team have gone on to lose the game on each occasion is surely no coincidence.
But at least Worcestershire have the confidence of knowing that the next one-day fixture, in 13 days' time, will be against those poor whipping boys, Bangladesh.