Saints were left facing an uphill task just 10 minutes in after defender Vestergaard was dismissed for a lunging challenge on Foxes striker Jamie Vardy on the edge of the hosts’ 18-yard box.
The Denmark international, who won the ball before catching Vardy with his studs as he followed through, was dismissed by referee Robert Jones following advice of VAR Jonathan Moss for denying his opponent a goal-scoring opportunity.
Southampton went down to 10 men early against Leicester, with Jannik Vestergaard sent-off
The Danish defender took a heavy touch and lunged on Jamie Vardy, but did get the ball first
Battling Saints overcame the setback to lead through James Ward-Prowse’s 60th-minute penalty and held on for a draw which moves them 10 points clear of the relegation zone following Jonny Evans’ equaliser.
Hasenhuttl hailed the heroics of his players but was less enamoured with the officiating.
Asked if he was pleased with the result, the Austrian replied: ‘Absolutely; not delighted with the red card decision but very delighted with the performance from my fighting side.
‘The official explanation was denial of a clear goal-scoring opportunity. The goalkeeper was near the ball, he could pick it up. I think he (Vardy) would never get this ball. This explanation is simply wrong.
Ralph Hasenhuttl was furious about the decision but delighted as his side held on for a point
The Saints defended superbly before James Ward-Prowse put them into the lead from the spot
‘I thought it was (going to be) a penalty and then it would be even more difficult but when you see the red card then you see that it was absolutely the wrong decision and we deserved to get something today.
‘Jon Moss has seen it, the VAR, and he says it’s a red card, although Vardy never had the ball. The denial of a clear goal-scoring opportunity is an argument that I cannot agree (with).’
Asked if he would appeal to prevent Vestergaard being suspended, Hassenhuttl replied: ‘Yes.’
Southampton had Ryan Bertrand sent off after 12 minutes the last time they hosted Leicester before collapsing to an embarrassing 9-0 drubbing.
The south-coast side look to have secured their safety after a difficult top-flight season
They were far more resilient on this occasion and, after Evans’ header swiftly cancelled out Ward-Prowse’s spot-kick, defended doggedly to avoid a 13th defeat from their last 16 top-flight outings.
‘It was an important signal that we can defend better than we have in the past when we were one man down and that we have a good start in the final six games (of the season),’ said Hasenhuttl.
‘It was a brave performance.’