Match ends, Southampton 0, Everton 3.
Everton secured their first victory at St Mary's in over a decade against a lacklustre Southampton as two goals from Romelu Lukaku caused the damage.
The Belgian's brace came from his first two shots on target, the first a wonderful header high into the net.
Everton counter-attacked ruthlessly and doubled their lead as Lukaku combined with Ross Barkley and struck low from the edge of the box.
Barkley added a third, another fine strike curled into the far corner.
Southampton may wonder if the result would have been different had goalkeeper Tim Howard not brilliantly saved Sadio Mane's thunderclap of a strike in the 20th minute.
But ultimately the hosts lacked variety in their attack against an effective Everton defence which secured only their second clean sheet in their last 18 league games away from home.
A performance to quieten the doubters?
A banner was flown over St Mary's stadium before kick-off as Everton fans organised a pre-match protest against chairman Bill Kenwright's regime.
"Kenwright & Co #timetogo" it read as some fans voiced their displeasure at the lack of funds made available to manager Roberto Martinez in the transfer market.
But should Martinez's men continue to perform as they did against Southampton, they will merely need fine-tuning rather than radical change before the transfer window closes.
Lukaku, performing with power and pace, was a danger throughout which led Barkley to say after the match that the Belgian is the best striker in the league when in such form.
Stones shines in defence
Everton have already rejected two bids from Chelsea for John Stones this summer, but the defender's assured performance against Southampton could quickly spark another substantial third offer from the Premier League champions.
As is becoming his hallmark, the 21-year-old was composed in possession, stealing the ball from the lively Sadio Mane when a slight misjudgement could have led to a penalty.
In search of a goal late on, Southampton were reduced to bombarding the Everton box with crosses but Stones and his partner Phil Jagielka were resolute, while Seamus Coleman and Brendan Galloway were indefatigable down the flanks.
"To keep a clean sheet when you come to St Mary's speaks volumes about the performance we had," said Martinez. "It's one of those games where you don't want to highlight an individual performance because that would be very wrong."
Worrying times for Koeman
Ronald Koeman, walking with crutches after an operation on an Achilles injury, will need a steadying aid for a defence which has now conceded in their last eight Premier League matches.
Despite monopolising possession for the majority of the first half, they were twice undone by a swift and clinical Everton.
The visitors scored their first with a move which started from a Southampton corner, while the second came after the Saints were caught in possession in midfield, setting the powerful Lukaku to bulldoze his way upfield.
It was unusual to see Southampton, a team which had not lost at home since their 2-0 defeat by Liverpool in February, struggling to create chances. Too often they relied on crosses to Graziano Pelle but the usually reliable Italian striker could not deliver.
Everton boss Roberto Martinez: "As a team we were outstanding in every department. The scoreline was the real truth. We were superior, we defended well, the intensity was incredible. On the counter-attack we looked unplayable at times. Many moments we were superior and that really pleases you."
Southampton manager Ronald Koeman: "I'm not angry. It's not normal because it's the start of the season and we know we can't compare to last season because we've got new players.
"Maybe to be a compact team, to be an aggressive team, we have to improve more than we at least showed in the first half. If you give them that space to play, if you make that kind of mistake, Everton have that kind of players to punish you and they did."
Man of the Match
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Lukaku struck a fan with a stray shot during the warm-up, but proved he's all heart by apologising and presenting a t-shirt to the woman in question. The home fans warmly applauded the striker's gesture, while manager Martinez later joked that his player would have to make hitting spectators with the ball part of his pre-match routine.
Watch Lukaku apologising to the fan via Twitter.
The stats you need to know
- Lukaku scored more than once in a Premier League game for the first time since his brace against Liverpool in November 2013
- Arouna Kone (three) has had a hand in more league goals in his last two appearances for Everton than he did in his previous 17 (two)
- Southampton have now gone eight Premier League matches without a clean sheet, conceding more than once in seven of them
- Saints have won just one of their last eight league games, losing five, drawing two and winning one.
- Ross Barkley scored and assisted in the same Premier League game for the first time in his career
- 2Cédric Soares
- 6José Fonte
- 33TargettBooked at 6mins
- 8DavisBooked at 77minsSubstituted forWard-Prowseat 79'minutes
- 11TadicSubstituted forRomeuat 45'minutesBooked at 49mins
- 7LongSubstituted forRodriguezat 72'minutes
- 19PellèBooked at 38mins
- 32GallowaySubstituted forBrowningat 88'minutes
- 16McCarthyBooked at 75mins
- 9KonéSubstituted forNaismithat 80'minutes
- 20BarkleyBooked at 45mins
- 10LukakuSubstituted forDeulofeuat 89'minutes
- Michael Oliver
- Shots on Target
Second Half ends, Southampton 0, Everton 3.
Foul by Oriol Romeu (Southampton).
Ross Barkley (Everton) wins a free kick in the defensive half.
Attempt missed. Jay Rodriguez (Southampton) right footed shot from outside the box is too high. Assisted by Oriol Romeu.
Offside, Everton. Tim Howard tries a through ball, but Steven Naismith is caught offside.
Corner, Southampton. Conceded by Tom Cleverley.
Substitution, Everton. Gerard Deulofeu replaces Romelu Lukaku.
Substitution, Everton. Tyias Browning replaces Brendan Galloway because of an injury.
Delay over. They are ready to continue.
Delay in match Brendan Galloway (Everton) because of an injury.
Attempt blocked. Graziano Pellè (Southampton) left footed shot from the centre of the box is blocked. Assisted by Sadio Mané.
Goal! Southampton 0, Everton 3. Ross Barkley (Everton) right footed shot from the centre of the box to the bottom right corner. Assisted by Seamus Coleman.
Attempt blocked. Tom Cleverley (Everton) right footed shot from the right side of the box is blocked.
Corner, Everton. Conceded by Matt Targett.
Attempt blocked. Romelu Lukaku (Everton) left footed shot from outside the box is blocked. Assisted by James McCarthy.
Attempt missed. Victor Wanyama (Southampton) right footed shot from the right side of the box is too high. Assisted by Sadio Mané following a corner.
Substitution, Everton. Steven Naismith replaces Arouna Koné.
Substitution, Southampton. James Ward-Prowse replaces Steven Davis.
Corner, Southampton. Conceded by Tim Howard.