Durham claimed an impressive win in a high-scoring encounter.
Lancashire defeated Derby by a handful of runs to win.
Surrey and Sussex claim victories.
Kent lost a rather close encounter against Gloucestershire.
Mujeeb had earlier this year made his IPL debut for Kings XI Punjab.
England will play Croatia in a bid to book their place in the FIFA World Cup final.
Rashid Khan, DJ Bravo and Carlos Brathwaite were among the top performers of the day.
Daniel Christian scored 113 in just 40 balls with seven fours and nine sixes against Northamptonshire.
His hat-trick helped Kent win the match by 6 wickets in the T20 Blast.
English batsman Joe Denly scored a century and picked a hat-trick in the same game.