Fulham failed to reproduce the form which saw them defeat Everton in midweek in an FA Cup replay and for much of the match they struggled to cope with a bright and inventive Southampton side, who lacked the final touch.
Saints manager Gordon Strachan again left leading scorer James Beattie on the substitutes bench and it was not until the 75th minute that the England striker was thrown into the fray, by which time it was almost too late.
Strachan preferred Brett Ormerod and Kevin Phillips as his attacking force and it seemed justified as Saints created one opening after another but had nothing to show for it.
Phillips headed onto the roof of the net in the 21st minute and then with a smart centre from the right touchline found Ormerod running free unmarked 12 yards out, but at full stretch his shot lacked power and direction and Van der Sar was able to save easily.
Phillips was involved again in the 41st when his pass from midfield sent Anders Svensson scampering clear but the ball bounced unkindly for the Swedish midfielder, enabling Van der Sar to make a superb save.
Jason Dodd, whose only goal in the last four years was wiped out by the Premier League's dubious goals panel, went close from 25 yards as Fulham had little option but to soak up the pressure.
The influential Steed Malbranque was booked for a foul on Marian Pahars on the half-hour and was unable to get a grip in the centre of midfield as he had done so often for Fulham this season.
The second half was much like the first with Saints making plenty of chances but not able to do anything with them.
Within seconds of the restart, Phillips eluded Ian Pearce on the right and cut in only for Van der Sar to stick out a boot and deflect the ball for a corner.
Then Rory Delap should have done better from six yards after being picked out by Phillips but the closest Southampton came to a goal was in the 56th minute.
Defender Michael Svensson saw his header from a corner by Dodd cleared from the line by Moritz Volz.
Fulham introduced Bobby Petta for Malbranque after 57 minutes and then Fulham survived a strong appeal for handball as Pearce controlled a centre from Pahars.
The longer the match went on the more confident Fulham became and towards the end of the match they began to respond to the exhortations of manager Chris Coleman to get forward by creating one or two clear chances.
American striker Brian McBride looked certain to score until his effort from ten yards was blocked by Danny Higginbotham and then goalkeeper Antti Niemi, who had nothing to do for 80 minutes was at last obliged to get down to keep out a low shot from Sean Davis.
Southampton forced ten corners in the second half, but found Van der Sar in imposing form while Zat Knight was an impressive performer in the air as Fulham held on to a hard earned point.
Southampton manager Strachan said: "We played the sort of football I like so there were no complaints there, but we just lacked the goals to go with it.
"I felt we had a strong case for handball, but overall we dominated the match and I have to be pleased with everything except the result because we should have won."
Fulham boss Coleman added: "We came under a lot of pressure, but I felt we responded it to it well. Southampton gave us little room, but we stuck at our tasks and I felt we were the stronger at the end."
Man of the Match: Edwin Van der Sar – a superb display in the Fulham goal earned his side a share of the spoils at St Mary's.