Aaron Burns scored two goals and Andrew Waterworth and Reece Glendinning added two late scores as Linfield started their campaign by beating Ballymena.
Midfielder Burns headed in from Kirk Millar's inswinging corner to give Warren Feeney's a 35th-minute lead.
Five minutes later Burns struck again after being set up by Stephen Lowry.
Striker Waterworth poked in a close-range goal five minutes from time and Glendinning made it 4-0 while Ballymena had defender Jim Ervin sent-off.
Former Linfield man Ervin pulled back Guy Bates who was in on goal in the 76th minute.
It was only the second time in seven years that Linfield have won their opening league games of the season.