Sampdoria vs Juventus: Cristiano Ronaldo met Alex Sandro's looping cross with an incredible leap and header just before half-time.
Gianluigi Buffon joined Paris Saint-Germain last summer and played 25 times in all competitions.
Gianluigi Buffon has not had the easiest of starts with PSG, shipping four goals in his first two friendly appearances against Bayern Munich and Arsenal.
Buffon, who played a record 176 times for Italy, has an option to extend his stay at the Parc des Princes for a further season.
The 40-year-old's contract with Juventus ended in June.
Gianluigi Buffon was substituted in the 63rd minute to take an ovation before 40,000 emotional Juventus fans many with their eyes brimming with tears.
Gianluigi Buffon will make his 640th Serie A appearance against Verona in Turin
Gianluigi Buffon's Champions League career looks likely to end in a red mist of rage after Cristiano Ronaldo's late penalty rescued Real Madrid from a pulsating Juventus comeback.
Buffon called time on his international career after Italy failed to qualify for the World Cup in Russia, losing a two-legged play-off to Sweden to miss the tournament for the first time in 60 years.
Cristiano Ronaldo, who also won the FIFA Men's Player of the Year award in October, added the 2017 Ballon d'Or to his previous wins in 2008, 2013, 2014 and 2016.
Buffon quit international football last month as four-time champions Italy sensationally missed out on their first World Cup finals in 60 years after a playoff defeat to Sweden.
Italy were held to a 0-0 draw in front of 74,000 fans at the San Siro on Monday, as they were unable to overturn a 1-0 deficit from the first leg in Stockholm.
The Netherlands, United States, Ghana and now Italy, a four-time champion and a pillar of soccer for almost a century, all will be absent from the 2018 tournament.
Italy need to overturn a 0-1 first-leg defeat to avoid missing out on the 2018 FIFA World Cup for the first time since 1958 when Sweden hosted the tournament.
The last time Italy failed to reach the World Cup was for the 1958 tournament in Sweden.
For football giants Italy the next few days could be a nightmare as they face a double-headed playoff against Sweden to avoid the humiliation of missing the World Cup for the first time in 60 years.
Holders Real Madrid face Atletico Madrid in the Champions League semi-finals as the city rivals do battle once more and French surprise-package Monaco take on Juventus, following the draw on Friday.