Image source, Getty Images

Sussex went top of the South Group with a seven-wicket win over Middlesex last night.

Captain Luke Wright, a centurion last Friday, made 47 from 33 balls to set up their successful run chase.

Sussex host third-placed Kent this evening, and a win for the visitors will take them top as Essex have other matters to attend to this week - namely a tour match against Australia.

Image source, Getty Images

Defending T20 Blast champions Birmingham Bears top the North Group with six wins out of eight, and tonight they're expected to give a home debut to New Zealand captain Brendon McCullum against bottom side Derbyshire at Edgbaston.

McCullum made just 18 against Lancashire a week ago but the Bears won by one run to continue their fine start to the competition.

Worcestershire and Leicestershire are only two points behind them, while only six points separate top from bottom.

As always, we've got every match covered in full by BBC local radio this evening.

BBC Radio 5 live sports extra will be live at Old Trafford from 18:15 BST for live coverage of Lancashire v Yorkshire.

Click on the Live Coverage tab to select your commentary of choice - our first batch of games gets under way at 17:30 BST. Team news on the way shortly...

Lancashire host Yorkshire in the north. Somerset face Gloucestershire in the west. Surrey play Middlesex in the south. And in the east...

Ah, that's where the theory falls down.

But in truth, every one of tonight's eight matches matter as we head towards the business end of the group phase, because almost all of the 18 teams involved in the competition have a realistic chance of qualifying for the quarter-final stage.

Image source, PA

Only five more days to go until England and Australia battle for one of the biggest prizes in sport.

It seems fitting then that, on the eve of the first Ashes Test, several local rivalries will be renewed during the latest round of T20 Blast fixtures.

Commentaries available on this page: (scroll through the live coverage tab to select your game)

Live scorecards available here

Lancashire v Yorkshire - Radio 5 live sports extra, BBC Radio Lancashire, BBC Radio Manchester and BBC Radio Leeds

Durham v Leicestershire - BBC Newcastle and BBC Radio Leicester

Somerset v Gloucestershire - BBC Somerset, BBC Radio Gloucestershire and BBC Radio Bristol

Nottinghamshire v Worcestershire - BBC Radio Nottingham and BBC Hereford and Worcester

Surrey v Middlesex - BBC London 94.9

Birmingham v Derbyshire - BBC Coventry and Warwickshire, BBC WM 95.6 and BBC Radio Derby

Hampshire v Glamorgan - BBC Radio Solent and BBC Radio Wales

Sussex v Kent - BBC Radio Kent