Stevie Eskinazi slammed 87 from just 37 balls as Middlesex racked up a record T20 Blast total in victory over Gloucestershire.
The Middlesex captain helped his side post 229-9 at Radlett before the visitors could only make 199-9 in reply.
England one-day captain Eoin Morgan also struck 41 from 24 deliveries as Middlesex bettered the 227-4 they made against Somerset at Taunton in 2019.
It was the fourth-highest T20 total conceded by Gloucestershire, as Benny Howell’s 46 from 20 balls came too late.
The visitors welcomed back many first-choice players after an injury-plagued, and winless, start to the season but it did not change their fortunes.
Having been sent in, Eskinazi showed his intent with three boundaries in the opening over and raised fifty in just 20 deliveries on route to his third-highest T20 score.
Three more matches are being played on the second night of the 2022 competition.
Leicestershire Foxes host Durham, Birmingham Bears play Northamptonshire Steelbacks and Sussex Sharks face Glamorgan.