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The Frenchman's first-half penalty was followed by two more strikes in the second period, while substitutes Eduardo Camavinga and Brahim Diaz also got on the scoresheet as Los Blancos continued their perfect start to the European campaign. 

Kairat threatened to take a shock lead after just nine seconds at the Ortalyq Stadion, with Dastan Satpaev's header going straight at Thibaut Courtois before Jorginho and Luis Mata failed to hit the target with their efforts in the opening seven minutes.

However, Madrid found its feet and took the lead just shortly before the half-hour mark. Franco Mastantuono was brought down in the box by goalkeeper Sherkhan Kalmurza, and Mbappe made no mistake from the penalty spot.

The 26 year-old doubled his tally six minutes into the second half, running onto a long ball from Courtois before lobbing the ball over Kalmurza. And he secured the match ball with an impressive finish into the bottom-right corner from the edge of the box.

Camavinga managed to flick Rodrygo's cross past the goalkeeper at the near post to make it 4-0, before Diaz fired home in the third minute of additional time to complete a successful trip for Xabi Alonso's side.

Mbappe has scored his fourth Champions League hat-trick, three of which have come in away games - the joint-most hat-tricks scored away from home in the competition's history, along with Filippo Inzaghi.

Courtois, meanwhile, became the second Madrid goalkeeper to assist a goal in the history of the Champions League, after Santiago Canizares against Olympiakos in October 1997.