The Blues have not won away from Goodison Park since last January and their early showing at St Mary’s showed that despite the potential glimpses of that record changing last weekend away at Crystal Palace, there is still a ways to go just yet.
Tadic gave the hosts the lead after 17 minutes following a decent spell of pressure from the Saints.
Jonjoe Kenny lost the ball on a counter attack, allowing Ryan Bertrand to break away. His one-two with Pierre-Emile Hojbjerg broke open the Everton defence and the left-back’s curling ball from the left found an on running Tadic.
The midfielder, after being able to beat Leighton Baines one on one, was able to roll the ball under Baines and past Jordan Pickford to give the hosts the lead.
Gylfi Sigurdsson, with his first Premier League goal of the season, levelled for Everton a handful of seconds into first-half stoppage time with a real goal of the season contender.
The Icelandic midfielder picked the ball up 30 yards from goals, glided forward a few yards before unleashing a vicious dipping effort from the right-hand side of the 18-yard box, hitting the underside of the crossbar and both posts before beating Fraser Forster to draw the Blues level.
Charlie Austin gave the home side their second lead of the game six minutes into the second half. Bertrand, with far too much time to cross, was easily able to deliver a ball into the Everton box.
Austin rose above Ashley Williams and glanced his header on to the ball and past Pickford.
The forward struck again minutes later, getting on the end of Tadic’s cross and powering his header low and away to the goalkeeper’s right.
Steven Davis added a fourth with four minutes left in the game, stabbing home from outside the Everton 18-yard box.
Saints dominate the early going
The home side, who are struggling themselves this season, dominated the early going and should have had more to show for their early endeavours.
Austin and Virgil Van Dijk both went close with chances from James Ward-Prowse corners. Austin lashed his rebounded attempt over the bar whilst the Dutch defender’s header went narrowly wide.
Austin also had a chance saved by Pickford when Steven Davis’ left-hand side free-kick beat every waiting player in the box and found its way to the English forward.
The Saints found plenty of joy down the Everton left-hand side, continually beating Leighton Baines two on one with the left-back lacking any sort of defensive support from the player in front of him.
Kevin Mirallas had the Blues; best chance of the half prior to the goal but after beating Cedric Soares, he overran his first touch, allowing Forster to be able to boot clear before the Belgian could shoot at goal.
Sigurdsson’s wonder strike moments before half-time only covered up the early Everton cracks that continue to the forefront each and every week.
Blues continue to slide
The watching Blues fans got neither.
Week after week, this Everton continues to lack the key needs that a side battling at the bottom end of the Premier League needs for survival.
After getting back into the game before half-time, there should have been a second-half bounce of confidence - pushing on to get a second of their own as they began to put their own foothold on the game.
Instead, Unsworth's side collapsed in a spectacular fashion allowing Austin to get two in less than ten minutes, effectively ending the game before the hour mark.