With the score level at 3-3, Murray had just secured a break point following a fall from Troicki that left the Serb clutching his left shoulder in pain.
Troicki called for a medical timeout but before play could resume the rain started to fall, sending the players scurrying back to the locker room.
They returned soon after when the drizzle relented, but before a ball was struck heavier rain began to fall and the sky turned increasingly black, prompting a delay of over an hour.
With little improvement in the weather forecast for Saturday, three-time Queen’s champion Murray faces the prospect of playing the rest of his semi-final and then the final in a hectic Sunday schedule.
That would be good news for South Africa’s Kevin Anderson, who earlier in the day booked his place in the final of the Wimbledon warm-up event with a 6-3, 6-7 (6-8), 6-3 win over French seventh seed Gilles Simon.