Messi and Ronaldinho were part of a legendary Barcelona team that conquered all before them from 2004 to 2008 - winning five trophies, including two LaLiga titles and the Champions League.
Messi - now at PSG after sealing a sensational free transfer from the Nou Camp this summer - was delighted to see the Brazilian legend again before he took to the field against Leipzig and they hugged before having a brief chat on the touchline.
Lionel Messi and Ronaldinho shared a heartfelt embrace before PSG's clash against Leipzig
The former Barcelona team-mates shared a brief word before Messi to to the field on Tuesday
The Argentine has not enjoyed the most of prolific starts to life in the French capital, but he netted a double against the German outfit on Tuesday night after striking in the last round against Manchester City, and Ronaldinho was in the stands to watch his old team-mate in action.
Messi's heroics ensured Mauricio Pochettino's side won 3-2, scoring a panenka penalty to help continue their run in the Champions League.
Ronaldinho spent five years at Barcelona, winning the Ballon D'or in 2005 and becoming renowned for his audacious skills, tricks and flicks - forming a devastating partnership with Messi and Samuel Eto'o.
Messi and Ronaldinho played together for four years in a devastating partnership at Nou Camp
Messi and Ronaldinho formed a deadly strike force with Cameroonian striker Samuel Eto'o (R)
He had made his name with PSG in 2001, earning rave reviews in France and playing 77 times, scoring 25 goals before Barca came calling in 2003.
Ronaldinho joined the Nou Camp at a time when Messi was just being introduced from the club's academy and he mentored the Argentine, with the pair enjoying a close friendship.
Earlier this summer - before Messi ended his 20-year stay with Barca - Ronaldinho had pleaded with his old team-mate to prolong his stay in the Catalan city, calling him 'the history of Barca'.
'He must stay, he is the history of Barca,' he told TuttoMercatoWeb.
'When Messi retires, which I hope will be in a long time, he can leave the No 10 there and nobody will touch it again.'