A creaking Andy Murray survived his second consecutive night-time scare on Pat Rafter Arena to stay alive at the Brisbane Tennis International.
Again troubled by injury concerns, Murray was forced to dig extremely deep to squeeze past Luxembourg's Gilles Muller 4-6 7-6 (7-4) 6-0 to book a place in the quarter-finals.
Like his tight opening-round win over world No.91 Mikhail Kukushkin, the top seed, returning from a groin problem, appeared in discomfort as he lost the first set to Muller.
The world No.54 broke Murray in the 10th game of the first set and then further stunned the Brisbane fans when he held a break point to go ahead 5-3 in the second.
But Murray rallied, sent the set to a tie-break, took control with an amazing reverse flick shot on the run and then swept through the third set against his downcast rival.
The win sets up a quarter-final against popular Cypriot Marcos Baghdatis who claimed the scalp of Japanese fifth seed Kei Nishikori in straight sets.