Surrey secured themselves a place in the quarter-finals of the Royal London Cup after beating Worcestershire by 36 runs at the Kia Oval.

A second-wicket partnership of 144 in 25 overs between Jason Roy and Kumar Sangakkara set Surrey on their way to a fifth win in six Group A matches, although they were given a scare by rock-bottom Worcestershire, who are now without a win in five games and effectively out of the competition.

Roy made 99 and Sangakkara, playing his last game for Surrey before going home to Sri Lanka for his final Test against India, 76 as Surrey, who also had useful contributions from Rory Burns and Gary Wilson, made 328 for 7 after winning the toss.

It seemed to be too many for Worcestershire but they responded magnificently, inspired by their captain Daryl Mitchell, who defied a pulled hamstring to score 59 off 63 balls with nine fours.

Youngsters Tom Fell and Joe Clarke kept up the chase by putting on 98 in 17 overs and Surrey were starting to fret until Sam Curran, Surrey's 17-year-old fast bowling prodigy, had Fell caught behind for 63.

Clarke went on to make 54 and Worcestershire were still in with a chance when Ross Whiteley was thrashing 35 off 24 balls, but when he was caught at long-on off James Burke it was the beginning of the end as they lost their last five wickets for 34 runs. Sam Curran finished with 3 for 49 for the hosts, while Burke took 3 for 51.

Earlier, Steven Davies, who had scored 99, 39, 98 and 115 in his previous four cup games, fell early to Jack Shantry for 13 and Roy was not as fluent as usual, but Sangakkara picked up the pace with a six off Saeed Ajmal.

Sangakkara cruised past fifty for the 115th time in 509 List A matches and was firmly on course for his 36th century when he was brilliantly caught by Mitchell, diving to his left at short extra cover but grasping the ball in his right hand.

Roy, who had reached 99 off 95 balls with 11 fours but was surprisingly nervous on the brink of his seventh one-day hundred, also fell to a superb catch. He got an edge trying to drive Joe Leach and wicketkeeper Ben Cox dived a long way to his right to snaffle the chance.

Surrey were stuttering at 201 for 3 but Burns and Wilson picked up the tempo. Burns had made 61 off 50 balls with seven fours when he was beaten by Ajmal's last ball, a sharply-turning off break, and swiftly stumped by Cox, whose impressive glove work also featured in three runs outs, including that of Wilson for 34.