Durham have qualified for the knockout stages of the Royal London Cup, but will have to wait until tomorrow to see who they will play in the quarter-finals.
The Riversiders completed their group games with victory over Surrey last week.
But the other sides in the nine-team group played last night.
It needed a Nottinghamshire win and a comfortable Somerset victory to stop Durham progressing.
The Cidermen lost an extremely tight game at Surrey by seven runs. Their target was revised after four overs were lost to a floodlight failure.
Notts’ win was as narrow, by one wicket off the final ball.
Yorkshire, Essex and Gloucestershire are in action as Group A reaches its conclusion. All are on ten points, but the Tykes have the better run rate. Durham play away to the team which finishes top, on Tuesday, Thursday or Friday of next week.