Kylian Mbappe scored four goals as Real Madrid edged out Olympiacos in a Champions League thriller.
The Greek hosts took an early surprise lead through Francisco Chiquinho's 20-yard strike.
But Mbappe stepped up for the visitors and struck three times in the space of seven minutes.
The Frenchman first ran on to Vinicius Jr's wonderful pass behind the defence to finish calmly - and then headed in Arda Guler's cross.
Mbappe looked unstoppable as he then beat the offside trap to net his hat-trick from Eduardo Camavinga's pass.
He then found Vinicius, who found the net, but his effort was ruled out for an offside against the French forward.
Aurelien Tchouameni hit the bar as Real - without five defenders and their first-choice goalkeeper through injury and illness - continued to dominate.
But a bullet header from substitute Mehdi Taremi got Olympiacos back into the game.
Mbappe bagged his fourth with a close-range poked effort from Vinicius' pass.
But Ayoub el Kaabi's header again gave Olympiacos late hope.
It ended a three-game winless run for Real in all competitions and marked their first competitive win in Athens in their 10th visit.
Line-ups
Olympiakos XI: D.García, Rodinei, Gelson Martins, Podence, Chiquinho, Retsos, Francisco Ortega, A. El Kaabi, Pirola, Tzolakis, Christos Mouzakitis
Subs: M. Taremi, Roman Yaremchuk, Strefezza, Costinha, Giulian Biancone, Diogo Nascimento, Santiago Hezze, Bruno Onyemaechi, Nikolaos Botis, Alexios Kalogeropoulos, Stavros Pnevmonidis, Lorenzo Scipioni
Real Madrid XI: F Mendy, Alexander-Arnold, Mbappe, Valverde, Lunin, Tchouameni, Vinicius, Camavinga, Güler, Álvaro Carreras, Raúl Asencio
Subs: Ceballos, Brahim, Fran García, Rodrygo, Bellingham, Gonzalo García, Endrick, Fran González, Javi Navarro
Doxmang
72
⭐️🇫🇷 Kylian Mbappé reaches 21 Real Madrid goals this season with 4 goals tonight! He’s currently top scorer of La Liga 🇪🇸 and Champions League 🇪🇺❤️🤜🏻🙌🏽👉
OluwasegunManU
55
Barca and RM need to really learn how to defend from PL clubs. I watched Barca yesterday, and I thought maybe it's because of the red card. But RM game today shows that there isn't any difference between Barca and RM defensively. Very poor defending, and using fullback as CB.......
Beickham
27
Click this to view GIFs: https://www.matchgif.com/v2/live/matchGifs?match_id=54252909&language=en
Nstech
20
As a Barcelona fan would gladly say Mbappe is a phenomenal player,I admire him 🔥