MADRID • Cristiano Ronaldo's gesticulations were borne out of frustration.
The persistent jeering by the Atletico Madrid faithful had been expected on his first visit to the Wanda Metropolitano stadium since leaving cross-town rivals Real Madrid for Juventus in the summer.
But all he had to show to the baying home fans was a five-fingered taunt to signify his five Champions League trophies as Juventus slumped to a 2-0 loss in the first leg of their last-16 tie on Wednesday night.
The seven-time defending Italian champions splashed out €100 million (S$153.5 million) on the Portuguese star forward in the hope that he would help them end 23 years of hurt in Europe's top club competition.
Instead, Ronaldo and Co are on the brink of elimination at the very first hurdle in the knockout stages.
Juventus were kept at bay by Atletico's rearguard before Diego Simeone made a shrewd tactical move with a triple attacking substitution - Angel Correa, Thomas Lemar and Alvaro Morata - after the break.
The breakthrough came in the 78th minute when Jose Gimenez scored after Morata's knockdown from a corner by Lemar.
Five minutes later, Diego Godin doubled their lead following a free kick, giving his team a huge advantage ahead of the March 12 return leg.
The Spanish LaLiga club have now kept a clean sheet in all three of their Champions League games against Juventus.
And they are unbeaten in their last 12 home matches in the knockout stages.
And Simeone, who provocatively celebrated Gimenez's opener by placing his hands over his groin, was delighted at how his players "represented the true meaning of Atletico".
Claiming he "felt the need to do it (the gesture)", the Argentinian said: "It wasn't aimed at the other team. Doing what we have done over these years is not easy, and today, we did it again."
While Simeone will be without Diego Costa and Thomas Partey through suspension in the second leg, he will be confident of repelling Juventus, who will not be able to call on the banned Alex Sandro in Turin.
Atletico are aiming to reach this season's final, which will be held in their stadium, and lift their maiden European Cup.