Middlesex 351 for 7 (Eskinazi 182, Malan 64, McKerr 3-38) beat Surrey 249 (Patel 118, Bamber 3-46, Yadav 3-52) by 102 runs
Stephen Eskinazi maintained his rich vein of form with a second successive century - and Middlesex's highest-ever 50-over score - to steer his side to victory in their Royal London Cup derby against Surrey.
The 28-year-old Seaxes skipper, who had struck his previous best of 146 not out three days earlier against Durham, eclipsed that effort with a majestic 182 at Radlett that included 17 fours and six sixes.
Eskinazi, who passed 1,000 List A career runs during his 136-ball knock, shared a third-wicket stand of 142 with Pieter Malan (64 from 60) and batted almost right through to underpin the Middlesex total of 351 for 7.
"I'm enjoying my cricket at the moment and feel like I'm playing with a sense of freedom," he said. "I guess I've got a bit of a point to prove after being left out of the Hundred and the best way to silence critics and put my name in that hat is to win games for Middlesex and put in performances like I did today."
Ryan Patel's resolute effort of 118 from 99 kept Surrey in the hunt but, once he was caught in the deep trying to force the pace, the visitors folded for 249 with 50 deliveries unused.
Invited to bat, Middlesex made a steady start as Eskinazi and Mark Stoneman put on 61, but they were pegged back by the introduction of Conor McKerr (three for 38).
McKerr's additional bounce took Stoneman by surprise and the left-hander slapped one to point, while Sam Robson played on after a brisk 18 that included a six and four off Nick Kimber.
However, that paved the way for Eskinazi and Malan to join forces and the pair calmly proceeded, with the South African advancing to his second half-century of the tournament.
Teenage spinner Yousef Majid - who bowled tidily to finish with two for 51 - achieved the breakthrough, trapping Malan leg before as he attempted to sweep and that triggered a middle-order Middlesex wobble.
With runs drying up and wickets falling regularly to Majid and Cameron Steel, the home side drifted to 273 for seven before Eskinazi regained the initiative in the death overs, slamming two McKerr full tosses over the fence.
Although Eskinazi departed with three balls remaining, Josh Blake pulling off an impressive one-handed grab behind the stumps, the captain's efforts were enough to lift Middlesex above the 350 mark.
Surrey were beset by problems at the start of their reply, with skipper Ben Geddes dragging on to Umesh Yadav in the third over and Steel forced to retire with concussion, having been struck on the helmet by a ball that leapt off a length.
Blake, who replaced the stricken Steel at the crease, was soon making the return journey after flashing outside off stump at his first ball from Ethan Bamber - leaving the visitors 23 for three in effect.
However, Patel rose to the challenge, clubbing Bamber for the first six of the innings and punishing some loose Martin Andersson deliveries as he and Tom Lawes (27) added 79 from 74.
The left-hander crashed consecutive leg-sixes off Yadav to reach his hundred, but he gradually began to run out of partners as Andersson's smartly-judged boundary catch removed Lawes and Bamber (three for 46) returned to bowl both Nico Reifer and Nick Kimber in his second spell.
Patel eventually skied Andersson into the hands of long-off and, although Middlesex were held up by debutant Nathan Barnwell's spirited 31 from 27, it was not enough to alter the outcome and Yadav (three for 52) wrapped up victory with two wickets in three balls.