The striker says his side are on a good run and are hoping to rectify the 3-2 Premier League defeat to Spurs they suffered at St Mary's back in December
Spurs ran out 3-2 winners in last year's clash at St Mary's Stadium in Tim Sherwood's first Premier League game in charge.
The hosts took the lead in that game but lost their way and were punished by Emmanuel Adebayor's double and a Jos Hooiveld own goal.
But Lambert, who scored Southampton's second goal in that match, is confident that he and his team-mates will provide the Londoners with a sterner test at White Hart Lane on Sunday.
"We're playing well at the minute, we've gone on a little run, which we were desperate for, and I think you'll see a different Southampton this time," he said in quotes reported by The Daily Echo.
"I don't think we were at our best when they played us at our place, and we were very disappointed with it, so we're looking forward to trying to rectify that."
Back-to-back league victories for Mauricio Pochettino's men have coincided with two losses for Tottenham, closing the gap between the clubs to eight points.
And Lambert believes his side can still reel in a few of the teams above them.
"I don't want to start saying we're aiming for fifth, because I think that might be a little bit too out of our reach, but I think seventh, maybe sixth, if we can finish in one of them positions that would be unbelievable," the striker added.
"I think if we finish eighth that's a good season, but because of where we are now we're going to try and push for them next positions now, and if we get seventh then we'll try and push for sixth."