The two performed their 1996 effort "Can't Knock This Hustle", while Jay Z also performed his hit "Public Service Announcement (Interlude)", reported Entertainment Tonight.
It marked the rapper's first stage performance in months and most public appearance since the release of Beyonce's "Lemonade".
The show also saw Diddy team up with Faith Evans to perform their Biggie tribute track "I'll Be Missing You".
Other surprise guests at the 20th anniversary concert to celebrate Diddy's Bad Boy Records included Lil' Kim, Nas, Usher and Busta Rhymes.