The Irish striker’s struggles in front of goal have characterised those of his team since the final weeks of the reign of Claude Puel.
Under Mauricio Pellegrino, they have become contenders for relegation, and after falling to 16th place as Palace rose to 14th with finishes from James McArthur and Luka Milivojevic, their supporters chanted for the manager’s sacking.
That Palace were involved in their third fixture in six days presented the hosts with a fine opportunity to end the winless run that stretched back to November and has led to growing pressure on his position. This was only the Saints’ second game in seven days.
If they were short on confidence, they recognised from kick-off the need to build on those circumstances and made a promising start.
They had already consistently probed when Oriol Romeu played a square ball across midfield to Pierre-Emile Hojbjerg, who in space from 25 yards unleashed a powerful strike the diving Wayne Hennessey did well to tip over.
Palace were already showing signs of fatigue — perhaps owing largely to the energy used holding Premier League leaders Manchester City to a 0-0 draw a little over 48 hours earlier — and in the 17th minute Southampton scored.
After Ryan Bertrand’s over-hit cross from the left was collected on the opposite wing by Jeremy Pied, the Frenchman played a low ball back into the area that was almost ignored by the visitors’ static defence.
Gifted both time and space, Long finally scored the goal that had eluded him for so long when, on the turn, he powerfully shot first time beyond Hennessey and inside the far right post.
It took until the 30th minute for Palace to have a sight on goal, when Andros Townsend’s curling effort was tipped wide by their former goalkeeper Alex McCarthy, and thereafter their energy gradually improved.
Roy Hodgson responded at half-time by replacing Yohan Cabaye with Patrick van Aanholt. Bakary Sako soon came on for Jeffrey Schlupp, but when Wilfried Zaha found Christian Benteke inside the area, the striker’s goal-bound shot was impressively tipped away by McCarthy from the bottom right corner.
The equalising goal they were beginning to threaten almost immediately followed. It was in the 68th minute, after Van Aanholt’s delivery had already been cleared, when Townsend chipped into the area, Benteke nodded into McArthur’s path, and the midfielder powerfully finished high into the roof of the net.
Palace have recently secured draws from losing positions against Bournemouth and West Ham, and victories over Watford and Stoke.
When Townsend squared to Milivojevic in the 80th minute another did not look imminent, but the Serbian struck first time and curled into the bottom left corner from 25 yards, securing another win and furthering Southampton’s misery.
McCarthy, Pied, Stephens, Yoshida, Bertrand, Romeu, Hojbjerg (Gabbiadini 75), Ward-Prowse (Davis 70), Tadic (Redmond 79), Boufal, Long.
Hennessey, Fosu-Mensah, Kelly, Tomkins, Schlupp (Sako 64), McArthur, Milivojevic, Townsend, Cabaye (Van Aanholt 46), Zaha, Benteke.