Austin came off the bench in the 79th minute to head home the winner three minutes from full time to hand the visitors the three points and heap further misery on United boss Van Gaal.
The result means that United have now only won two of their last 10 Premier League games and is sure to continue the uncertainty about Van Gaal’s future at the club.
However, former Tottenham boss Hoddle appeared to be delighted to see Austin net the winner and says that Southampton’s signing of the forward is the deal of the season.
Hoddle tweeted after the final whistle:
What a start for Charlie Austin ! Well done , great lad and will score goals in the PL no doubt . And 4 Million , deal of the season .
— Glenn Hoddle (@GlennHoddle) January 23, 2016
The result – the Red Devils’ sixth defeat of the season – left United in fifth place in the Premier League table and five points behind Tottenham in fourth.
MORE: Latest Man Utd news
MORE: Latest Arsenal news
MORE: The latest football news