Surrey are closing in on a third successive County Championship title after cruising to a 10-wicket win over Durham with a day to spare at The Oval.
Durham, who began the third day trailing by 152, never recovered after losing two wickets in the first over to Dan Worrall.
Worrall and Sam Curran, in only his second Championship appearance of the season, each took four wickets as Durham were dismissed for 177 in their second innings with only Emilio Gay (48) offering prolonged resistance.
That left Surrey needing just 25 to complete their eighth win of the campaign and skipper Rory Burns and Dom Sibley knocked off the target in five overs.
It was their sixth victory at The Oval this season with only Somerset, who drew in April, denying them a clean sweep on home turf.
Surrey picked up 23 points which took them onto 221, 31 clear of Somerset with their match at Old Trafford still in the balance.
Surrey face Essex at Chelmsford in the final round with Somerset hosting Hampshire.
The tempo was set in the first over when Worrall made a double breakthrough, Dan Hogg losing his leg stump and Ben McKinney beaten by a fine delivery.
Durham had lost three wickets in first half hour when Jordan Clark bowled Alex Lees.
David Bedingham only got half-forward to Curran’s sixth ball and was lbw while Ollie Robinson was also beaten by late inswing and lost his off stump to leave Durham’s innings in disarray at 74-6.
Gay, making his Durham debut before his permanent move from Northamptonshire this winter, shaped up well and added 46 with Bas de Leede either side of lunch to give Durham hope.
But Worrall returned at the pavilion end to remove Gay before another Curran in-swinger accounted for De Leede. Tom Lawes produced a fine delivery to force James Minto to edge to keeper Ben Foakes.
Curran finished things off with another booming in-swinger that was way too good for Chemar Holder before Surrey cruised to their tiny target.
