Yorkshire 261 (Masood 63, Crocombe 4-47) beat Sussex 212 (Clark 55) by 49 runs

Both sides contributed significantly to this sun-kissed Group B fixture played out in front of a 3,417 crowd at the Minster City's Clifton Park.

The Vikings then sealed their second win in three matches as Bess, who earlier hit 37 with the bat, struck twice with his off-spinners in Sussex's 212 all out in 44 overs.

The Vikings looked well set at various points on a pitch offering something for everyone having been inserted, only to lose wickets when acceleration looked likely.

New ball seamer Ari Karvelas struck after only six balls when he bowled Will Luxton, who played around one angled into the him - two for one.

Masood and Fin Bean shared a steadying 51 for the second wicket, while the captain later added 60 for the third with James Wharton, who contributed 38.

But the cases of Bean and Masood best summed up Yorkshire's progress.

Bean was dropped on nought at deep backward point in the second over, but he couldn't take full advantage - caught behind off Karvelas for 37, leaving the score at 53 for two in the ninth over.

Masood, having reached a 68-ball fifty, was later run out coming back for two to deep backward square-leg - 170 for five in the 36th.

Harry Duke and Bess both batted positively for 38 and 37, taking their side up to 250 with a seventh-wicket 61.

While Karvelas struck twice, fellow seamer Danial Ibrahim was excellent for one for 29 from his 10 overs. But Crocombe was the pick.

He had Matthew Revis caught at deep midwicket in the 40th over before adding his other three in the 48th and 50th, bowling Duke and getting Dan Moriarty and Ben Coad caught. Bess was also run out as one of three final-over wickets.

Yorkshire started their defence with two wickets in the opening seven overs - 23 for two.

Tom Haines was run out at the striker's end by a direct hit from backward point having initially turned for a single before aborting mission, and talismanic seamer Coad bowled Henry Rogers for a duck.

But Sussex hit back, and with gusto as Clark and wicketkeeper-batter Charlie Tear added a dynamic 95 stand inside 17 overs for the third wicket.

Both were strong through the off-side, and Clark reached his fifty off 58 balls with a six over deep square-leg off Bess on his competitive captaincy debut in place of rested John Simpson.

However, Bess would gain revenge not too long afterwards.

In successive overs from the City End, he had a sweeping Tear caught at deep backward square-leg for 43 and then Clark caught at cover as Sussex slipped to 123 for four in the 25th over.

From there, Yorkshire put the squeeze on an inexperienced Sussex middle and lower order.

Coad had Zach Lion-Cachet caught behind and left-arm spinner Dan Moriarty trapped Ibrahim lbw in successive overs - 161 for six after 33.

Oli Carter played nicely for 43, but he couldn't provide the dynamism the Sharks required. And when he tried, he holed out to deep square-leg off Moriarty, leaving the score at 198 for seven in the 42nd.

Revis, Hill and another run out followed as Yorkshire triumphed.