Surrey 199 for 6 (S Curran 68, T Curran 50) beat Middlesex 126 (Holden 43, Jack 3-17, Atkinson 3-20) by 73 runs
Jacks, who had made two swashbuckling half-centuries in his last three innings against Middlesex at Lord's in the format, came out swinging from ball one and while he played and missed at a few the England man took heavy toll of a full toss from Helm, belting it back past the bowler for four.
Teenager Fernandes, thrown on in the powerplay, struck second ball when pinch-hitter Sunil Narine hit him straight to cover, but Jacks sent two drag-downs from legspinner Luke Hollman into the stands, before a brilliant catch by Helm on the fence at long-on ended his revelry.
The Currans' progress was steady initially, but the 12th over bowled by Ryan Higgins changed the complexion as Tom Curran dispatched the allrounder to all parts, hitting five fours in succession. Not to be upstaged Sam Curran then cut loose, denting Fernandes's excellent figures to that point with consecutive sixes.
Blake Cullen, back on Middlesex first-team duty for the first time in more than a year, was rusty and his 11-ball over, including a waist-high full toss and four wides only added to Surrey's momentum.
The 100-stand came in 56 balls, and we were in the penultimate over by the time Tom top-edged a steepling catch back to grateful bowler Higgins. Sam, too, left before the end as the south Londoners finished one shy of 200.
For Middlesex much depended on skipper Stephen Eskinazi, but he departed for just 1, run out following a mix-up from the fourth ball of the innings.
The exciting Joe Cracknell deposited a short one from Sean Abbot into the second tier of the Mound Stand only to perish trying to repeat the feat meaning both openers were gone with 27 on the board.
Pieter Malan, back from injury, also found the stands before departing to Atkinson for a breezy 30, and Jacks then struck twice in his first over, removing the dangerous Higgins, caught at mid-off before bowling Hollman round his legs.
Throughout this period Holden had hit bravely, smiting two big sixes at a strike rate approaching 200, but when Narine bowled him for 43 the game was up.