Looking to build on Sunday’s win against the same opponents ahead of the World Cup qualifying tournament, a depleted Scottish side instead suffered a humbling four-wicket reverse.
Without leading strike bowlers Ali Evans and Stuart Whittingham, the Scots were powerless to prevent their hosts romping to a 300-run target.
Rameez Shahzad led the way with a superb century as the Scottish bowlers toiled.
His third-wicket stand of 125 with Ashfaq Ahmed took the game away from the Scots after Scott Cameron and Mark Watt had each claimed a scalp.
Ahmed was eventually caught by Michael Leask off Safyaan Sharif, having hit a punishing 92 with eight fours and three sixes.
But Shahzad steered his side home with a superb unbeaten 121, facing just 115 balls and hitting ten boundaries and two maximums.
Earlier Scotland squandered the chance to put the game beyond their rivals with a dreadful late collapse. They had set the platform for a total in excess of 325 by reaching 250-4 with ten overs remaining.
Skipper Kyle Coetzer delivered a hard-hitting 75 which included 13 boundaries before Richie Berrington hit a superb 90 and looked on course for a seventh international century until being bowled by Mohammed Naveed.
The Clydesdale player had hit nine boundaries and two maximums.
George Munsey took up the attack by plundering 47 from only 29 balls but when the Watsonians man was out in the 41st over Scotland lost their way.
Craig Wallace, Sharif and Michael Jones departed in consecutive overs as the Scots failed to press the accelerator and had to be content with 299-9. The Scots head home today before travelling to Zimbabwe next month for the World Cup Qualifier.