Mane Stars as Liverpool Run Rampant Over Watford
A run of three draws in four league matches had seen Liverpool's advantage over Manchester City trimmed to a point heading into Wednesday's fixtures.
However, Liverpool never looked like a team in danger of cracking under the pressure as Mane's brilliant brace - highlighted by a stunning backheeled finish for his second - put them in command.
Divock Origi put the result beyond doubt in the second half and a pair of late headers from Van Dijk completed the rout.