The outcome of the match could have been different had Murray won the first set, as he really should have done.
On the first of two set points when leading 6-4 in the tie-break, Murray planted a volley into the net with the court gaping, drawing shrieks from the shocked crowd and leaving the Scot covering his face with his hand.
Murray went on to lose the set and was suddenly chasing the match.
Neither player was able to break serve in a tight second set before Murray, with confident hitting and delicate touches, levelled after making a fast start in another tie-break.
Having not faced a break point since the third game of the match, Murray lost serve for 1-0 – shortly after taking a tumble on his right ankle – and an increasingly confident Mensik moved a double break up at 5-2.
But Murray, just as he did to stop Mensik serving out the first set, used his vast experience to fight back.
Sensing nervousness down the other end of the court, Murray increased the aggression of his groundstrokes to pile on the pressure but he could not maintain the momentum in the tie-break as Mensik regained his composure to seal a memorable win.
Murray’s frustrations were clear as he made a sharp exit after a tense contest lasting three hours and 23 minutes – the longest match in the Qatar Open’s history.