Chelsea got proceedings underway with a 2-1 home win over Manchester City on Friday, while on Saturday Arsenal hammered promoted London City Lionesses 4-1 before Vignola grabbed the headlines with her electrifying display for Everton on Sunday.
Liverpool's Cornelia Kapocs got the hosts off to a great start at Anfield by firing home off the underside of the crossbar in the 12th minute, but that was as good as it got for the Reds as 20-year-old Vignola took centre-stage.
The winger, who was born in Uruguay but represented Spain at under-age level, ran at Ceri Holland before curling home a brilliant equaliser in the 24th, and captain Katja Snoeijs headed a superb second to send Everton into the break 2-1 up.
Vignola then flashed a header into the net nine minutes after the restart to make it 3-1 and secured her hat-trick with a deflected effort two minutes later to complete the rout.
In Manchester, French forward Melvine Malard scored two late goals as United mauled Leicester City 4-0, while Bethany England netted a late penalty to give Tottenham Hotspur a 1-0 win over West Ham United in their London derby.
On the south coast, Brighton & Hove Albion were held to a 0-0 draw at home by Aston Villa, the only one of the six games on the opening weekend of the 12-team league without a goal.