Surrey eased to a seven-wicket victory at the Oval to inflict a third straight CB40 defeat on Scotland.
England hopeful Jade Dernbach claimed impressive figures of two for 13 from his eight overs as Surrey restricted Scotland to 196 for nine.
Josh Davey top-scored for the visitors with 50, while Calvin Burnett added a late 31 not out.
But, despite the loss of Rory Hamilton-Brown on a total of six, Surrey recovered to 200 for 3 after 33 overs.
The partnership of Steven Davies, who was caught out for 96, and Jason Roy, caught for 60, put the home side on the front foot.
And the combination of Zander de Bruyn, who finished 32 not out, and Tom Maynard, who was only required to contribute five runs, saw Surrey over the winning line.
Gordon Goudie took two wickets at the expense of 51 runs for Scotland, who have 24 hours to recover before facing Warwickshire.
Yasir Arafat was similarly expensive for Surrey as he finished with three for 60.