The East Lancs Road was left covered in oil after an HGV broke down.
The lorry was travelling eastbound towards Manchester about a mile from the Haydock Island junction when it developed a mechanical problem.
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The entire eastbound carriageway was left covered in the thick black substance.
The incident happened at around 4am on Sunday.
Fire crews from Leigh and Wigan stations had to use absorbent material to mop up the oil as best they could and make the road safe for motorists once again.
The painstaking operation took around an hour.
Fortunately there was very little disruption to traffic as it was in the early hours of the morning.
Highways officers also attended the scene.
Emergency services left the scene at around 5am.