Marcelo Bielsa's side claimed all three points against the Saints in a result that saw the West Yorkshire outfit once again climb into the top half of the standings.
Goals from Patrick Bamford, Stuart Dallas and winger Raphinha pushed the Whites to victory in LS11 as Leeds continue to impress on their return to England's elite division.
It was a night of brilliant goals, lovely tributes and a return to winning ways for Bielsa... here are the best pictures from the lens of Yorkshire Evening Post photographer Bruce Rollinson as we look back on a great night for the Whites.
1. Warm-ups
Leeds United warm-up at Elland Road.
2. Bielsa looks on
The Leeds United head coach barks instructions from the home dugout.
3. VAR review
Referee Andre Marriner consults VAR after giving a penalty for Southampton as Nathan Tella falls under the challenge of Diego Llorente. It's overturned!
4. Unbelievable tackle
Leeds United winger Raphinha bursts through on goal and looks for all the world like he will score until a stunning challenge from Oriol Romeu.
5. Bamford celebrates
Just minutes into the second half and Patrick Bamford strikes with a lovely goal. A nice assist from Tyler Roberts, too.
6. Bamford mobbed
Celebrations continue at Elland Road.