The Italian pair played together at Lazio back in the early-to-mid 1990s and have now reunited in Montreal with Nesta making his bow at Saputo Stadium on Saturday.
The Impact managed a morale-boosting 3-1 home win over New York Red Bull with Di Vaio finally getting on the scoresheet in his eighth appearance for the club and Nesta was happy to see him in form.
"I felt really happy for him," Nesta said. "It's been a few games already and he hadn't scored, but he finally has, and in a very important game against New York."
Di Vaio opened the scoring in the 48th minute, two minutes before Davy Arnaud made it 2-0, which preceded Thierry Henry's 11th goal of the season for the Red Bulls with Sanna Nyassi putting on the finishing touches with just over 15 minutes remaining.