The visitors pressed home their advantage after the break as former Foxes midfielder N'Golo Kante, gifted time and spacespace, drilled home a drive from 30 yards.
Deep into the second-half, one of the West Ham analysts complained Ronaldo was 'killing us in that pocket' and Ronaldo's deep position for the winner drew two defenders and freed up space for Cavani and Martial down the left.
Theo Walcott gave Arsenal the lead after a nice one-two with Alexis Sanchez, before Chuba Akpom took advantage of some calamitous defending to give the Gunners breathing space.
Batshuayi then scored twice in the final 15 minutes - firing in from outside the box after being picked out in space by Bakayoko and then scrambling home Zappacosta's cross.
In a repeat of the 2016 Europa League final, which the Spaniards won in Basel, Argentine midfielder Joaquin Correa cut through the Liverpool defence and curled home a cool finish to clinch a point.
It made it three wins on the bounce for Liverpool after losing 3-1 at Arsenal last month and built further momentum as they gear up for Sunday's EFL Cup final against Chelsea at Wembley.