Liverpool produced a high-energy home display to take a two-goal lead into the second leg of their Europa League last-16 tie against Manchester United.
Daniel Sturridge opened the scoring from the penalty spot, converting after Memphis Depay fouled Nathaniel Clyne.
Roberto Firmino doubled the lead after a poor clearance by Michael Carrick.
David de Gea made a string of good saves as Liverpool dominated, with the away side managing just one shot on target.
The second leg is at Old Trafford on Thursday, 17 March (20:05 GMT kick-off).