Coach Luis Enrique has slashed Mbappe's minutes in recent weeks after the player told the club he would leave at the end of the season, but the France captain proved he will be vital if PSG are to finally win the competition for the first time.
The electric Mbappe was impossible for Real Sociedad to shackle and his strikes after 15 and 56 minutes left the Ligue 1 leaders with a simple night in the north of Spain. "We are very happy, it was the objective," Mbappe told Canal Plus. "We wanted to qualify but today we also wanted to win and give ourselves a bit of an easier game.
That is what we did. "We had a clear game plan. We managed to score early and, above all, we managed to avoid getting into any major difficulty." Heavily linked to Real Madrid, the determined Mbappe gave La Liga's defences a glimpse of what horrors may await them next season.
The forward, who also netted in the first leg, fired over in the opening stages and then blazed past Hamari Traore to set up Bradley Barcola, but Alex Remiro denied him from point-blank range.