Worcestershire made it three wins in a row to stay top of the North Group, with Lancashire just behind them after their comfortable win over Northants.
Martin Guptill marked his return to Derby by steering Worcestershire to a third consecutive victory in the Vitality Blast by six wickets to leave them top of the North Group.
The former Derbyshire opener adjusted to a slow pitch with a run-a-ball 65 as the Rapids overhauled the Falcons' 135 for nine with eight balls to spare.
Dillon Pennington impressed on his T20 debut with two wickets for 22 runs and although Anuj Dal made 35 from 26 balls on his first Falcons appearance, the home side were at least 20 runs short of a challenging total.
Lancashire are second after their spinners set up a comfortable eight-wicket home win over Northamptonshire.
Liam Livingstone's fielders also rediscovered their best form, as the visitors were limited to 123 for nine in their 20 overs - a target which Lancashire's batsmen overhauled with 23 balls to spare.
Alex Davies made 64 not out to record his second consecutive T20 half-century.
Ed Pollock's blistering start and unbeaten half-centuries from Ian Bell and Adam Hose lifted Birmingham Bears to a comfortable eight-wicket victory over Yorkshire at Edgbaston.
Pollock's 39 off 14 balls - plus composed knocks from Bell (50no) and Hose (51no) saw the Bears ease to a 158-run victory target with 25 balls to spare.
Yorkshire totalled 157 for seven thanks principally to Gary Ballance's high-class 79 from 49 deliveries.
Defending champions Nottinghamshire completed a second successive victory, winning at neighbours Leicestershire by 19 runs.
The visitors' total of 199 for eight was based on a partnership of 97 for the third wicket between Samit Patel (52) and Tom Moores (51).
The hosts collapsed from 80 for two to 102 for six in pursuit of a 200-run target which did not look unattainable on a good wicket and with a lightning quick outfield.
Sussex captain Luke Wright led by example at Sophia Gardens as his team gained their second win from two games with victory over Glamorgan to stay top of the South Group.
Wright's 88 from 53 balls was the highlight of an impressive team performance in an eight-wicket victory.
After scoring 173 for four, with Colin Ingram top-scoring with an undefeated 81, the hosts were let down by some poor bowling as Wright and Laurie Evans shared a match-winning partnership of 123 in 12.4 overs.
Kent, too, continued their perfect start as they beat Somerset by eight wickets at Taunton.
The hosts, who have not beaten their opponents in the shortest format since 2011, posted 159 for six after losing the toss - James Hildreth top-scoring with 57 off 45 balls and Carlos Brathwaite claiming four for 21.
In reply, Kent made light work of their target, charging to a convincing win with 21 balls to spare.
Michael Klinger's assured half-century saw Gloucestershire resume their Twenty20 hoodoo over Middlesex with a comfortable six-wicket win at Uxbridge.
Last season's loss at Gatting Way was Gloucestershire's first in 12 T20 contests between the two sides.
Thanks to Klinger's 58, that result proved the exception rather than the turning of a tide.
For the hosts the only cause for cheer was a belligerent 33 in just 12 balls from James Fuller, back playing again after an 18-month injury absence.