Yet again CIYMS had fluctuating fortunes on the second day of the European Cricket League group stages in Spain.
The first game of the day saw Jacob Mulder claim four wickets to restrict Istanbul to what appeared a very modest 78 for 8 in their 10 overs.
However the Belmont side's top-order found the going equally tough as they struggled to 40 for 3 after seven overs, needing 39 from the last three.
Carson McCullough looked to have won the game with a boundary blitz, as 27 came from the eight over, leaving the equation at 12 from 12 balls - routine, surely?
McCullough's dismissal for 36 off 17 balls (2 fours, 4 sixes) saw the momentum swing once again, with CIYMS only managing six runs from the last two overs to fall five runs adrift.
They picked themselves up with a powerful end to the day as they powered to a convincing eight-wicket win over Punjab Lions of Nicosia (Cyprus).
Three wickets apiece for Adam Kennedy (3-8) and Mark Best (3-12), plus two more for leg-spinner Mulder (2-19) kept the Cypriots to 84/9.
Adam Kennedy
The CIYMS reply got off to the worst possible start as Chris Dougherty was run out without facing, and it appeared it could be another of those days.
Jason van der Merwe had other ideas, as he thumped 5 sixes and 4 fours in an unbeaten 54 from 25 deliveries, dominating a second wicket stand of 61 in 32 balls with Carson McCullough (23).
CIYMS sealed the emphatic win with 14 balls to spare.
They are back in action on Saturday when they will be hoping to gain revenge over Portuguese side Oeiras in the Eliminator match.