Arguably the greatest comeback of all, this one is so iconic that it has its very own title in France and Spain – La Remontada (The Comeback).
PSG were clinical at home, winning 4-0, but the Nou Camp sensed something special when Luis Suarez scored after just three minutes in the second leg.
Barcelona were two goals to the good at the break courtesy of a Layvin Kurzawa own goal, but still trailed by two goals on aggregate.
Lionel Messi scored a penalty soon after the restart but Edinson Cavani hit back to silence the home faithful, although it wasn’t the pendulum-swinging moment PSG hoped for.
Barcelona, now trailing 5-3, needed three goals in fewer than 30 minutes to achieve a miracle. Neymar scored a free-kick in the 88th minute to offer further hope, before the Brazilian stroked home a 91st-minute penalty to level the tie at 5-5 on aggregate.
But PSG were still heading through on away goals.
Then, with 20 seconds of added time remaining, La Remontada came to fruition when Sergi Roberto turned home Neymar’s chipped pass, with Barcelona becoming the only team in history to overturn a four-goal Champions League deficit.