After a blistering start to the season, Southampton were looking to continue their run of form knowing that a win would take them to third place - for a short time at least.
Fulham were looking to build on the win against Crystal Palace on Monday, but the Saints dominated from the start and scored when Jay Rodriguez flicked on a James Ward-Prowse corner for Rickie Lambert to head home.
The goal came after Fulham midfielder Scott Parker told Dimitar Berbatov to mark the England striker from Ward-Prowse's corner, only for the Bulgarian to stand and watch the ball fly over his head for Lambert to nod in unopposed at the far post.
Fulham struggled to get the ball out of their half and Southampton nearly added a second but Morgan Schneiderlin's effort was cleared off the line. The home side continued to pour forward with full-backs Nathaniel Clyne and Luke Shaw constantly attacking down the flanks.
Rodriguez was denied by Maarten Stekelenburg after surging clear, and Victor Wanyama sent a low shot skidding wide and Lambert fizzed another effort against the post. Two minutes before half-time, Lallana lifted the ball to the back post, where Lambert deftly nodded it back across goal for Rodriguez to head home from close range.
The visitors did not manage a shot on goal in the first half due to the high-tempo passing game of Southampton and the home side continued to search for a third goal. The result was never in doubt as Southampton kept pressing and Rodriguez flashed an acrobatic effort wide.
Artur Boruc was finally called into action after 75 minutes, but only to deal with Dejan Lovren's attempted clearance from Amorebieta's cross.
The Cottagers finally managed an effort themselves with eight minutes left, when a corner was not properly cleared and Sidwell hooked the dropping ball wide. However, the result was never in doubt and Saints now sit fifth after the weekend's fixtures.
Write for GiveMeSport! Sign-up to the GMS Writing Academy here: http://gms.to/1a2u3KU