Surrey secured their place in the knockout stages of the Vitality Blast after beating Sussex by four wickets.
Chasing 166 to win, opener Will Jacks hit 65 off just 39 balls before Jamie Overton made an undefeated 40 to guide Surrey to victory with five balls to spare.
Tom Helm was the bowling hero as Middlesex dented Kent's Vitality Blast qualification hopes by landing a tense two-run win in Canterbury.
Set a target of 185 at an asking rate of 9.25 an over, the Spitfires slumped to their second successive home defeat after failing to score nine runs needed for victory off Helm's nerve-tingling last over.
Jordan Cox ended a near-heroic run chase unbeaten on 39, while skipper Daniel Bell-Drummond went for a season's best 89 in trying to slog Helm's first delivery of the final over.
Aron Nijjar celebrated career-best bowling figures as Vitality Blast holders Essex Eagles thrashed Hampshire by 54 runs to keep their slim quarter-final dreams alive.
Spinner Nijjar ripped through a shaky Hampshire batting line-up with figures of 3-22, while Jack Plom celebrated his maiden professional wickets to take 2-18.
Tom Westley had earlier clubbed his first half-century of the year, with Dan Lawrence marooned on 49, as Essex reached 168 before Hampshire could only manage 114-9 in response.
Yorkshire had to make do without four key players again due to Covid-19 protocols as they lost to Durham by 43 runs at Emerald Headingley.
The club confirmed that Matthew Fisher, Tom Kohler-Cadmore, Josh Poysden and David Willey were advised to self-isolate for 14 days, ruling them out of the rest of the group stage, with Willey announcing on Twitter that he had tested positive for coronavirus.
The Vikings struggled without them again, having lost their last game to Lancashire, as they were dismissed for 104 in the 17th over in pursuit of 148 - Matty Potts and Paul Coughlin with three wickets each for Durham.
Plus, Babar Azam blasted 114 not out from 62 balls as Somerset posted 183-3 before dismissing Glamorgan for 117 to give themselves an outside chance of progressing from the Centeal Group.