The Saints, who no longer have the threat of the drop hanging over them following Fulham’s relegation on Monday, went behind in the second minute when Christian Benteke out-muscled their defence to score with a thumping left-footed shot.
Ings, who had been out of action since tweaking a hamstring against Tottenham Hotspur in late April, levelled in the 19th minute, catching the Palace defence flat-footed as he controlled the ball before swivelling to fire home.
Nathan Redmond upended Wilfried Zaha to concede a penalty just before the break, but Southampton keeper Fraser Forster dived smartly to his left to keep out the resulting spot-kick from Luka Milivojevic.
In the second half, it was Southampton’s turn to get off to a fast start and they scored two minutes in with a cleverly worked corner from James Ward-Prowse that was played into Che Adams, who steered the ball home from a tight angle. With Palace floundering, Ings toe-poked his second in the 75th minute to lift Southampton to 14th spot in the table on 40 points, one behind 13th-placed Palace.
