Adam Scott has taken a five shot lead in the Qatar Masters.
The 21-year-old had seen his four-shot advantage over main challenger Colin Montgomerie halved before he had teed off, the Scot picking up birdies at the first and third.
But Scott was quickly into his stride and as Montgomerie faltered with a bogey on the fourth and two birdies of his own restored his cushion over the seven-time European number one.
Scott began the day three shots clear of the field after rounds of 67 and 66 gave him an 11-under-par halfway total of 133.
And the Australian had stretched his advantage to five shots midway through Saturday's play.
A birdie on the eighth took Montgomerie to the turn in 34, and another birdie on the 10th took him to 10-under-par for the tournament.
Not to be outdone, however, Scott matched those birdies on eight and 10 and at 15-under, and was five shots ahead of the field.
Montgomerie had been joined on 10-under by compatriot Stephen Gallacher and Anders Hansen, the Dane seemingly losing his way with bogeys on the eighth and ninth before a run of eagle-par-birdie from the 10th got him back in contention.