Ronnie O'Sullivan crashed to a 4-1 defeat to Neil Robertson in the second round of the Ladbrokes World Grand Prix in Preston.

The Australian raced into a 2-0 lead following two half-century breaks of 80 and 70, with O'Sullivan rarely getting a chance to leave his seat.

The two cuemen were not at their fluent best in the next, with both players missing feasible shots, but Robertson came out on top to nudge into a 3-0 lead thanks to a score of 43 to finish the third frame.

Robertson, the world number seven, put himself in a commanding position in the fourth to go 53-11 up but O'Sullivan fought back to need just the pink to take his first frame.

A poor positional shot from Robertson gave him a chance of the whitewash.

A tactical battle ensued with the remaining pink and black, O'Sullivan eventually prevailing to earn a lifeline, but that remained short-lived as Robertson rattled off an 83-break to reach the last eight.

World number four Judd Trump fell at the second hurdle following a 4-1 defeat to Barry Hawkins, who will play Robertson for a place in the semi-finals.

Hawkins opened the match by taking the first frame courtesy of a break of 64 and followed that up with a run of 86 in the next before Trump replied with the only century break of the match - a clearance of 107 - to reduce the scores to 2-1.

But the Ditton potter responded with another two half-century breaks of 73 and 72 to secure his place in the quarter-finals of a ranking event for a second successive time.