In front of thousands of delighted Barcelona fans, who turned up to celebrate the team's magnificent treble, the World Cup winner thanked the singer who performed at Ronaldo's controversial birthday party back in February.
After thanking the Barcelona staff and his teammates, Pique decided to play the role of stand-up comedian, joking: "and to Kevin Roldan, he started all this!"
Ronaldo was criticised for his decision to host his 30th birthday party hours after Real Madrid's humiliating 4-0 defeat to local rivals Atletico Madrid at the Vicente Calderon - even though everything had been pre-arranged.
A number of Ronaldo's teammates decided not go, feeling it was inappropriate to celebrate after such a heavy defeat, while those who attended were criticised by fans and the press alike.
Reports at the time also claimed Real Madrid would fine both James Rodriguez and Sami Khedira for attending while carrying injuries - although it's still unclear whether formal action was actually taken.
Pique's comments unlikely to sit well with Ronaldo
Pique wouldn't have meant any malice towards his former Manchester United teammate Ronaldo; the pair of them have always been mutually respectful of one another despite the intense rivalry that exists between Barcelona and Real Madrid.
But his tongue-in-cheek comments are unlikely to go down well with Ronaldo, who won the Pichichi but failed to end the season with one of the major team trophies.
This ultimately cost Carlo Ancelotti, a coach Ronaldo was very close to, his job last month.
The three-time Ballon d'Or winner now finds himself under the management of former Liverpool boss Rafael Benitez - and how that particular relationship pans out promises to be one of the most fascinating sub-plots of the 2015-16 campaign.
Real Sociedad defeat was turning point for Barcelona
Whether or not Ronaldo's ill-timed birthday party was the moment that changed the respective seasons of Real Madrid and Barcelona is up for debate.
Certainly the biggest moment of Barcelona's season came in January, at Real Sociedad's Anoeta, where Luis Enrique's side suffered a surprise 1-0 defeat.
Resolving the strained relationship between Enrique and Lionel Messi was key - and after this happened, everything began to fall neatly into place for the Catalan giants.
Real Madrid are likely to respond to Barcelona's treble success with at least one big-name signing - potentially Juventus midfielder Paul Pogba - while Ronaldo will be hungry to exact revenge on Pique, and his Barcelona teammates, next season.
Was Cristiano Ronaldo's birthday party the turning point in the seasons of Real Madrid and Barcelona? Have your say in the comments below!