(CNN) -- Cristiano Ronaldo underlined just why Real Madrid agreed to pay him the big bucks on a scintillating evening of European football. 

The 28-year-old, who inked a new five-year deal with the Spanish club on Sunday, completed a brilliant hat trick as Real raced to a 6-1 rout against Galatasaray. 

Ronaldo had the final say in Istanbul as he danced past three defenders before blasting the ball into the net for his hat-trick. 

Summer signing Isco had got Los Blancos off the mark when he picked up a long ball hit from beyond the halfway line by Angel di Maria and hit home after 33 minutes. 

From then on it was one way traffic as Karim Benzema and Ronaldo added two goals apiece before Umut Bulut pulled one back for the Turkish champions. 

The away victory saw the nine time European champions kick off a new era of European football under manager Carlo Ancelotti in some style. 

A pulsating opening round of Champions League group matches featured a flurry of firsts. 

Former Barcelona boss Pep Guardiola safely negotiated his first match in charge of Bayern Munich's title defence with an emphatic 3-0 win over CSKA Moscow. 

David Alaba hit home a dipping free kick to set the Germans on their way before Mario Mandzukic powered in a header in a dominant first half. 

Arjen Robben volleyed in a scooped pass from Alaba to tick off a first European win for Guardiola and his defending champions. 

David Moyes also came through his first game as Manchester United manager unscathed as the club made its first European outing without Sir Alex Ferguson at the helm since 1985. 
What team does he play for?
Real Madrid agreed to pay him