The strikes arrived in succession just past the hour mark of what had been a hard-fought game at Craven Cottage in front of watching England manager Roy Hodgson.
Once one goal had gone in though, the efforts flowed for Mauricio Pochettino’s men. Lallana set Southampton on their way, as the skipper marked his 250th appearance for the club with a well-taken low strike from Lambert’s pass that beat Maarten Stekelenberg at the far post.
An unrelenting spell from Saints drew two further efforts. Lambert struck his 100th league goal for the club and his third successive goal against Fulham, with a shot on the turn to convert substitute Nathaniel Clyne’s cross, before Jay Rodriguez added a sublime third with a curling shot into the top corner.
The quick-fire goals settled what had been a tough assignment up until that point with Saints grateful to the display from Artur Boruc in the opening 45 minutes as he notably saved well from Darren Bent on two occasions.
Saints hadn’t won a league game at Fulham since October 1947, but went on to record a double of victories over the Whites this term to condemn the hosts to the bottom of the Barclays Premier League table.
Mauricio Pochettino made two changes to the team that started the 2-2 draw with Arsenal. Victor Wanyama and Rickie Lambert returned to the eleven, with Jack Cork and Sam Gallagher dropping to the bench.
Of Fulham’s six transfer deadline day signings, only two were eligible to play, and both Lewis Holtby and William Kvist were named in the starting line-up for the hosts, supporting Scott Parker, Steve Sidwell and Damien Duff in midfield.
Hosts Fulham got the match underway with Darren Bent and Lewis Holtby taking the first touches on halfway as they attacked the end housing the Southampton fans behind Artur Boruc’s goal.
Rene Meulensteen’s side searched for a quick start as Damien Duff held the ball from kick-off to try and release Bent for an early attack on Boruc, but the over-hit pass gave the Polish keeper a comfortable first touch of the match.
Saints made a bright start with Wanyama’s presence giving the visitors a solid protection to the back four as the home side tried to move the ball around.
Scott Parker’s speculative shot was easy for Boruc to gather, but Calum Chambers conceded the first corner of the game by clearing Bent’s dangerous cross in the eighth minute. Holtby swung the delivery in and towering defender Dan Burn headed the ball onto the roof of the net, as Saints were given an early warning.
Saints responded at the other end with Jay Rodriguez’s low cross which Whites midfielder Steve Sidwell skewed towards his own goal where Maarten Skelenberg had to be alert for a quick reaction save.
The visitors won their first corner in the 13th minute after Lambert, Schneiderlin and Chambers linked up neatly before the latter’s cross was deflected behind.
The resulting set-piece saw Schneiderlin hurry his shot, which he knocked wide of Stekelenberg’s right post.
It remained an open and competitive affair as the game reached quarter of an hour. Sascha Riether zipped another encouraging looking cross for the hosts across the Saints area before Parker was given an opportunity to deliver from a free-kick conceded by Rodriguez who was booked for a clip on Holtby.
A far too casual flick from Yoshida presented Sidwell with an opportunity to strike at goal moments later, but the shot dragged well wide of the target.
Chambers flashed a low drive wide at the other end before Boruc was alert to pluck Holtby’s through-ball away from the clutches of Bent, as the striker continued to try and pounce in behind the Saints backline.
Bent nodded over from another cross, and the resulting corner drew a terrific one-handed save from Boruc as he clawed away Brede Hangeland’s powerful header just outside the six yard box.
Wanyama followed Rodriguez into the referee’s notebook for a lunge on Parker in Fulham’s half, and on the half hour Saints won their second corner when Luke Shaw’s deep cross was knocked over on the byline.
That was the first of two quick-fire set-pieces for the visitors, and after the second one, Jose Fonte remained in an advanced position to deliver the ball back into the box, where fellow central defender Yoshida headed wide from ten yards out.
With just over half an hour played, there was still little to choose between the two teams, but in the middle of two treatment spells for Yoshida and Wanyama, Saints were indebted to Artur Boruc for two fine saves.
The Pole was at full stretch to keep out Bent’s volley from Parker’s clever flick, and the goalkeeper was at his best again a minute later to make a block at his near post from the Fulham striker.
Schneiderlin was the third Saint to be cautioned when he brought down Sidwell, as the visitors weathered a brief storm from the Whites.
Lambert almost found Rodriguez with a cross from the right for a chance to test Stekelenberg from close range, before Fonte picked out the striker with a high delivery which Rodriguez headed wide.
A Lallana cross from the left was narrowly missed by Rodriguez as the club’s top scorer edged closer to finding the target, but as yet to no avail.
The half-time whistle sounded soon after, with Saints grateful one hand to Boruc, but certainly well in the game as the teams went into the break.
HALF-TIME: FULHAM 0-0 SOUTHAMPTON
Pochettino made a change at the interval with Jack Cork replacing Wanyama in midfield for the second 45 minutes.
A promising break forward led by Luke Shaw presented Saints with their first opportunity of the half when his pass intended for Lambert ran through to Rodriguez, who drilled a low shot across the face of goal as the game picked up from where it left off before the break.
Cork’s impact on the game was instant, as he picked Rodriguez out on the left with a sweeping pass from halfway. From there, Rodriguez laid the ball back to Lallana, who teed up Schneiderlin for an acrobatic overhead kick which just cleared the crossbar.
Saints were showing renewed fight in a game which remained fiercely contested.
On 58 minutes the visitors made their second substitution when Chambers was replaced by Nathaniel Clyne to inject some fresh pace down the right channel as Saints combatted the threat of Kieran Richardson.
Lallana drew a smart save from Stekelenberg with a stinging shot after Schneiderlin had played the skipper through on goal, and Fulham’s Dutch keeper was tested again when Rodriguez dinked a shot on target.
Fulham were given a let off when Lambert slipped inside the area as Rodriguez lifted the ball back into the area, but Saints soon made their pressure count when they took the lead on 64 minutes.
A move which started in midfield, led to Lambert playing in LALLANA on the left flank. The skipper took one touch to take the ball in his stride before flashing in a low strike to the bottom right corner for 1-0.
Fulham immediately switched Duff with Clint Dempsey in the aftermath of the goal, but Saints were now rampant in attack as they went in search of a second strike.
Lambert and Lallana combined again for the former to nod the ball back to Steven Davis, whose low strike was deflected wide for a corner.
From the set-piece, Schneiderlin saw a header cleared from the line as he connected to Davis’s delivery, and Saints went close again when Luke Shaw cut the ball back for Rodriguez, but the striker couldn’t turn it goalwards as the ball slid out of play.
The second goal duly arrived however, with 70 minutes on the watch. Clyne and Davis linked up for the former to cross into the area where LAMBERT made no mistake with a low finish for his third successive goal against the Whites in the Premier League.
Pajtim Kasami replaced Scott Parker with just over 15 minutes remaining with the hosts desperate to shore themselves up as they struggled to stem the tide.
But the icing on the cake for Saints was applied in the 76th minute when Lambert played an impeccable pass over the left back to release RODRIGUEZ who skinned Hangeland before curling a wonderful finish over Stekelenberg for 3-0 from the edge of the area.
Still not content with their lot, Saints pushed on again, with Sidwell needing to make a vital interception to deny Lallana from finding a way through again.
Fulham’s last change saw Kvist replaced by Muamer Tankovic for the final seven minutes, with damage limitation in order for the hosts.
Sam Gallagher came on for Rodriguez with just over three minutes to play, and the youngster was flagged offside for his only opening of a brief spell which saw Saints see out the game comfortably, including the three additional minutes of stoppages.
FULL-TIME: FULHAM 0-3 SOUTHAMPTON
Fulham team: Maarten Stekelenberg, Sascha Riether, Dan Burn, Brede Hangeland (c), Kieran Richardson, Scott Parker (Pajtim Kasami 74), Steve Sidwell, William Kvist (Muamer Tankovic 83), Lewis Holtby, Damien Duff (Clint Dempsey 65), Darren Bent
Unused substitutes: David Stockdale, Alexander Kačaniklić, Hugo Rodallega, Josh Passley
Southampton team: Artur Boruc, Calum Chambers (Nathaniel Clyne 58), Maya Yoshida, Jose Fonte, Luke Shaw, Morgan Schneiderlin, Victor Wanyama (Jack Cork 46), Steven Davis, Adam Lallana (c), Jay Rodriguez (Sam Gallagher 87), Rickie Lambert
Unused substitutes: Kelvin Davis, Jos Hooiveld, James Ward-Prowse, Guly do Prado
Goals: Lallana, 64; Lambert, 70; Rodriguez, 76
Referee: Mike Jones