United dominated the latter stages, and the 33-year-old Cavani struck again in stoppage time, stooping to head past Saints keeper Alex McCarthy.
Manchester United's Edinson Cavani celebrates scoring their second goal. (Reuters image)
Substitute Edinson Cavani produced a second-half masterclass, scoring twice and creating another goal as Manchester United hit back from a two-goal deficit to beat Southampton 3-2 in a Premier League cracker on Sunday.
Southampton had looked in control after Jan Bednarek headed in James Ward-Prowse’s corner in the 23rd minute before Ward-Prowse beat De Gea 10 minutes later with a curling free kick.