Taylor smashed a career best 80 from just 41 balls, including seven fours and five sixes, as the hosts recovered from 61-6 to 155-8 with nine balls remaining.

But both Andrew Tye and Jack Taylor were run out in the penultimate over to leave Gloucestershire 19 runs short and ensure Durham would become the third side from the North Group to reach finals day.

Earlier, another Taylor – Jack’s brother Matt – was the pick of the Gloucestershire attack, finishing with 2-28 from his four overs.

Mark Stoneman (61) and Michael Richardson (37) top scored for Durham, who will now join Northamptonshire and Nottinghamshire at finals day in September, with the fourth team still to be confirmed.