Pakistan star Babar Azam hit a century to reignite Somerset's fading hopes of reaching the T20 Blast last eight.
Babar's stunning 114 not out from 62 balls - his third T20 Blast ton in 11 matches - helped Somerset end a run of three defeats as they hammered Glamorgan in Cardiff by 66 runs.
Surrey are now through in South Group after beating Sussex and there were also victories for Middlesex and Essex.
Durham's win over Yorkshire means that Notts qualify in North Group.
The Outlaws are now guaranteed to finish in one of the top two slots - and may need to win only one of their remaining two games to ensure that they head the group and guarantee a home quarter-final.
Durham's 43-win over still weakened Yorkshire in Leeds lifted them to third, two points behind Lancashire, and leaves the Vikings needing to win both their last two games to stand any chance of qualifying.
In Central Group, Somerset are now within two points of both second-placed Northants and third-placed Birmingham Bears.
And, in South Group, Surrey are two points clear after beating Sussex by four wickets with five balls to spare at the Oval, thanks to Will Jacks' 65 and some spectacular late firepower from Jamie Overton.
Surrey lead Kent, who lost a last-ball thriller by just two runs to Middlesex earlier in the day, only their second South Group defeat, with Sussex still a further point behind in third.
Sussex are now only a point better off than Middlesex, who are two clear of holders Essex, who kept their faint hopes of qualifying for the knockout stages alive with a 54-run win over Hampshire in Southampton.
They can still scrape through if they win their last two and other results got their way - but that is no different to the scenario they faced 13 months ago. when they went on to win.
Babar at his best
Babar made the fourth highest score in two decades of Somerset T20 cricket to help them to 183-3, hitting five sixes and nine fours, after being dropped twice.
He was supported for the second half of their innings by 19-year-old debutant Lewis Goldsworthy, who contributed 38 not out to an unbroken stand of 90.
Glamorgan were then bowled out for just 117, Craig Overton taking three of the wickets, with 25 balls of their innings unused - and that significantly improves Somerset's run rate.
"Catches win matches," said Glamorgan head coach Matthew Maynard. "And, when you drop the world's best T20 opener in the third over, you are going to suffer. The fielding was poor, and it has to improve."
Surrey's fifth straight win
Surrey made it five wins in a row as they saw off Sussex at the Kia Oval, with Liam Plunkett in their side for the first time this season.
Jacks followed up his 55 against Middlesex on Monday with a blistering 65 off just 39 balls before Overton, dropped on 12, cashed in with an unbeaten 40.
Chasing Sussex's 165-7, Jacks was bowled by Will Beer in the 12th over, having just hit the leg-spinner for his third six. But, with 62 still needed off eight overs, although Rikki Clarke was caught in the covers, Overton and Jamie Smith got the job done.
"I love my batting," said Overton. "I see myself as an all-rounder, so it's nice to show what I can do. The opportunity to do that is one of the reasons why I joined Surrey."
Finding form too late?
Essex failed to win any of their first six games before finally breaking their duck against Sussex on Monday - and they followed that up by proving far too good on the day for Hampshire.
Tom Westley (51) put on 57 in 6.5 overs with Cameron Delport, who was caught off spinner Mason Crane for 31, then Dan Lawrence (49*) and Ryan ten Doeschate shared an unbroken stand of 58 to help Essex reach 168-3 - and Hampshire never got close.
England batsman James Vince was among the early casualties, caught behind down the leg-side for a first-ball duck before spinner Aron Nijjar took 3-22 to limit the hosts to just 114-9.
Final over costs Kent
Middlesex reached 184-5 against Kent after Joe Cracknell smashed 50 off 22 balls and John Simpson and Luke Hollman (both 46) shared a 70-run stand before both were run out.
England's Zak Crawley, who made a stunning unbeaten 108 in Kent's previous game , this time only faced two deliveries before holing out at mid-on for a single and at 94-5 in the 14th over, they were well behind the required rate before Daniel Bell-Drummond and Jordan Cox added 82 in 6.4 overs.
They needed just nine off the last six balls, but Bell-Drummond flashed a catch to point, departing for 89, and Grant Stewart was run out, leaving Cox stranded at the wrong end on 39 for the final delivery, from which Matt Milnes could only manage a single, instead of the boundary they required.
Yorkshire beaten by Durham
Even though Yorkshire were forced to play for the second game running without Tom Kohler-Cadmore, David Willey, Matthew Fisher and Josh Poysden because of Covid-19 guidelines, they still limited to Durham to just 147.
But the hosts never recovered from losing their first three wickets for 22, including their skipper, former England Test opener Adam Lyth, Harry Brook and the world's top rated T20 batsman Dawid Malan.
And, with Matthew Potts taking three wickets, they were well short on 104 all out.
Thursday, 17 September (start times BST)
18:00 - Notts Outlaws v Derbyshire Falcons - Trent Bridge
18:35 - Lancashire Lightning v Yorkshire Vikings - Old Trafford