MELBOURNE: Danielle Collins won a battle of attrition in scorching heat to overhaul Elise Mertens 4-6 6-4 6-4 and book her second quarter-final at the Australian Open on Monday.

In a gruelling clash of former semi-finalists, the American 27th seed snatched the win with a barrage of power hitting as Mertens served to stay in the match.

Belgian Mertens saved two match points, the second with a gutsy second serve, but then surrendered meekly on the third with a double-fault.

Collins downs Danish teen Tauson to set-up Mertens last-16 clash

Collins will play the winner of Simona Halep and Alize Cornet for a place in the semi-finals.