Mane caused an upset for Manchester City as his hat-trick puts the chances of Pellegrini’s men qualification for the Champions League in a tight situation.
Southampton secured an easy 4-2 win for Koeman’s side with Shane Long striking at the near post and Mane doubled the lead from 10 yards before Manchester City’s Kelechi Iheanacho secured City’s first goal before half time.
Mane was quick in the second half to score twice and to make sure of the win, reacting quickly as Jose Fonte’s header came off the crossbar and converting Dusan Tadic’s pass.
Though Iheanacho found the top-right corner in the 78 minutes of play, it was late and made no significance to the already lost match.
The victory ensures Southampton are hopeful for a place in Europa with two points adrift of sixth-place West Ham and with two games remaining.
Manuel Pellegrini whose side have a champions league match on Wednesday against Real Madrid complained that England’s fixtures should allow for enough rest before such crucial tie. “Real Madrid played their domestic league match on Saturday, giving them extra 24 hours rest ahead of the tie, while so is not applicable to them.