A first-half hat-trick from Ollie Watkins helped Aston Villa to a stunning 7-2 victory over Liverpool in the Premier League on Sunday to end the champions' 100 per cent start to the season in extraordinary fashion. Liverpool began badly at Villa Park as a poor pass from Adrian - deputising for Alisson in goal for the visitors after the Brazilian picked up a shoulder injury - gifted Watkins his the opener in the fourth minute. A full-strength Liverpool defence was carved open again moments later with on-debut former Everton midfielder Ross Barkley dragging his shot wide after being gifted another chance. If there was an element of good fortune about Watkins's first goal in a Villa shirt, his second was all his own fine work as he cut inside before firing into the top corner to stun the champions and make it 2-0 in the 22nd minute. Mohamed Salah's fine left-foot finish seemed to get Liverpool back in the game in the 33rd minute but John McGinn's deflected strike two minutes later restored Villa's two-goal advantage. Watkins completed a perfect hat-trick inside 39 minutes with his head, becoming the first player to score a Premier League treble against Liverpool in over a decade, and Barkley made it five 10 minutes into the second half. Salah did give Liverpool hope on the hour mark but a late double from Jack Grealish completed the scoring, condemning the champions to their first seven-goal defeat in a match in any competition since 1963: a 7-2 loss at Tottenham Hotspur. Villa rained in 18 shots on the Liverpool goal and could have added more before the final whistle as they climbed to second in the standings after a third successive win. Liverpool are fifth.