The Belgian struck twice and Ross Barkley completed the scoring as Roberto Martinez’s side put in an exceptional first half performance away from home
A dominant display from Romelu Lukaku helped Everton to a 3-0 victory over Southampton at St Mary’s.
Lukaku opened the scoring, heading a perfect Arouna Kone cross beyond Maarten Stekelenburg from close range after a sweeping counter-attack.
And the Belgian doubled the lead before half time, latching on to a Ross Barkley pass to beat Stekelenburg with a well-taken first time shot.
Graziano Pelle went close and Southampton gave Oriol Romeu a debut as they attempted to find a way back into the game, but Barkley made sure of the win late on with a cool finish.
Lukaku signalled his intent early on, his powerful run halted by Matt Targett’s foul just outside the area before Barkley’s free-kick clipped the wall and deflected over the crossbar.
Everton were pressed into defensive action in the 14th minute when Pelle’s downward header picked out Dusan Tadic, but his shot was blocked and the visitors scrambled the ball clear.
Pelle, with three goals in the opening three games of the season, then failed to connect properly with a back-post header and flicked it harmlessly wide of Howard’s right-hand upright.
The hosts continued to force the issue and Sadio Mane brought an excellent stop from Tim Howard with a low close-range effort, before Southampton were caught on the break.
Barkley set Arouna Kone – the visitors’ only change from the opening day after his late leveller from the bench against Watford – free down the right following a Southampton corner and his superb delivery was expertly headed home by Lukaku, who was quick to acknowledge the quality of the assist.
Martinez’s men should have extended their lead just before the half-hour mark, but Barkley’s tame strike from the middle of the area was saved by Stekelenburg and Tom Cleverley put the rebound wide.
Lukaku did make it 2-0 on the brink of half-time, though, stroking his shot past Stekelenburg after gathering Barkley’s pass.
New Saints signing Romeu was introduced for Tadic for the second half and Koeman’s charges started brightly, with Pelle’s half-volley stinging Howard’s palms.
The Italian carried his side’s most potent threat, heading another chance over the bar in the 66th minute as Southampton looked to breach an Everton outfit with only one clean sheet in their last 17 away league matches.
Mane went close, bringing a full-stretch save from Howard from distance, but Barkley’s fine right-footed finish put the result beyond doubt in the 84th minute.
For Martinez, who has promised new arrivals, it was a demonstration of the quality already at his disposal, while Southampton’s focus will now switch to the first leg of their Europa League qualifier against FC Midtjylland on Thursday.