Adam Hose hit 110 not out off 53 balls as Birmingham Bears stormed to the top of North Group table by crushing neighbours Worcestershire for a Midlands derby T20 record 144-run win.
The Bears cashed in on Lancashire's slip-up at Derby to leave the top three all on 16 points, a point ahead of Yorkshire, while Notts also won.
In South Group, already qualified leaders Surrey lost again, to Essex.
Hampshire and Somerset won to further heat up the race for a top-four finish.
Surrey remain the only side to have definitely booked a quarter-final berth after Lancashire failed to get home against Derbyshire, with big-hitting Tim David crucially stuck at the non-striker's end for the final five balls of the last over bowled by George Scrimshaw.
Lancashire's failure to book their place in the last eight allowed the Bears to sneak above them in a one-sided affair at Edgbaston - a game of five golden ducks as Alex Davies, Sam Hain and Carlos Brathwaite all suffered first-ballers for the hosts, followed by Worcestershire skipper Brett D'Oliveira and Dwayne Bravo.
"That was the best night of my career," said Bears all-rounder Dan Mousley. "To win against Worcester at a packed Edgbaston is a great feeling. I was very pleased to score some runs but then getting Moeen Ali with my first ball topped it."
Hosts Birmingham resoundingly won the Bears-Pears derby with Worcestershire at Edgbaston as they handed out a record 144-run defeat to the visitors.
Hose became the first to hit two centuries for the Bears in 20 years of T20 cricket as he made 110 not out to help his side post 228-8 - their sixth 200-plus total this season, more than any other side in the competition.
After slumping to 3-2 when Mitch Stanley removed both Davies and Hain first ball, the Bears' cornerstone was a stand of 91 in nine overs between Hose and Mousley, who hit his first T20 fifty of the summer.
But Worcestershire were no match for the hosts, buckling to 19-3 inside five overs, including the loss of England all-rounder Moeen, who was making only his fifth appearance in 12 games in this year's T20 Blast.
Following the end of his IPL commitments with Chennai Super Kings, Moeen missed all four of Worcestershire's opening four games, all away from home.
He then played the next four before missing a further three following a direct clash with England's three one-day internationals against The Netherlands in Amsterdam.
But sadly for the visitors he failed again, holing out to Mousley off his eighth ball for 4 to leave him with just 48 runs from five knocks - and, aside from Colin Munro's 34, the 2018 winners folded cheaply to 84 all out, comfortably the Pears' worst defeat in this competition - and the Bears' best.
Yorkshire Vikings made it two victories in successive nights as they won by 62 runs against Northamptonshire Steelbacks, who suffered an untimely third straight defeat.
The Tykes made a nightmare start at Wantage Road as they were reduced to 11-3 inside their first 19 balls.
But they still piled up 190-7 thanks largely to England T20 international Harry Brook bashing six sixes in his 67 off 31 balls.
He was well supported by Matthew Waite (35 not out off 20 balls), Northants-bound skipper David Willey (31) and Jordan Thompson (30).
Waite then took 3-18 and Willey 2-24, backed by two wickets each for Dom Bess and Shadab Khan as the hosts were shot out for just 128.
Derbyshire had a 99-run third-wicket stand between skipper Shan Masood (75 off 50 balls) and Wayne Madsen (70 off 31) to thank for a competitive score of 188-8 against Lancashire.
But David smashed an unbeaten 42 off 23 balls to help reduce the target to 33 off four overs - and leave the visitors looking favourites to secure a quarter-final.
Scrimshaw, who had gone for 48 from his first three, bowled a superb final over, conceding only five off it as David, who had taken a single off the first ball, stood helpless at the wrong end.
Durham and Notts Outlaws were badly delayed by the weather at Chester-le-Street, in a game which eventually got underway as an 11-over-per-side contest.
Steven Mullaney's 34 not out helped Notts run up 98-9 - and the visitors then held their nerve in the final over to edge out a narrow two-run win.
Aaron Beard took a career-best 4-29 as Essex took a big stride towards the quarter-finals with a 43-run win at Chelmsford over Surrey, who lost for the second time in successive nights after winning nine of their first 10 games.
Beard removed three of Surrey's top four as the North Group leaders were held to just 155-9 in pursuit of 199.
Michael Pepper struck 48 from just 18 balls with six fours and three sixes and Paul Walter hit 49 from 33 with four sixes to propel Essex to 198-7
One more win from their last two games will seal a place in the quarter-finals for the Eagles.
Somerset should join Surrey in the last eight after winning a seven-over contest against Glamorgan following rain in Cardiff.
They slipped to 15-4 batting first before Tom Abell swung away for 26 in 14 balls and Tom Lammonby made 18 from nine to raise Somerset to 75-6.
Glamorgan could only manage 56-5 despite Colin Ingram's unbeaten 37 in 19 balls, and Somerset can only now be denied a top-four spot on net run-rate.
Hampshire are also well-placed to reach the last eight after Ben McDermott's return to form led them to a crucial nine-run victory over Gloucestershire.
After just 17 runs in his last five innings, the Australian made 50 from 38 balls before some late hitting from James Fuller (22 from 14) helped Hants post 178-7, having been asked to bat.
Gloucestershire were always behind in the chase and despite Benny Howell's last-ditch 34 in 13 balls, they could only reach 169-7 as Hampshire leapfrogged their opponents into the top four.
Any hopes of qualification have long since gone for defending champions Kent Spitfires.
But Joe Denly's 58 from 39 balls did at least help them to just a third game in defence of their T20 Blast title as they chased down Sussex's 158-8 to win by six wickets, reaching 159-4 with seven balls to spare.
Next T20 Blast fixtures - Friday 1 July
Worcester: Worcestershire Rapids v Lancashire Lightning (17:30)
Lord's: Middlesex v Somerset (18:15)
Leicester: Leicestershire Foxes v Northamptonshire Steelbacks (18:30)
Trent Bridge: Notts Outlaws v Durham (18:30)
Headingley: Yorkshire Vikings v Birmingham Bears (18:30)
Kia Oval: Surrey v Kent Spitfires (18:30)
Ageas Bowl: Hampshire Hawks v Gloucestershire (19:00)
Hove: Sussex Sharks v Essex Eagles (19:00)