Frances Tiafoe sealed the title for Team World with victory over Stefanos Tsitsipas.
Djokovic announced his withdrawal from the year's last Grand Slam tournament on Twitter.
The three-day team event pits six of Europe's top players against six from the rest of the world.
The Serb beat the Australian in four sets, 4-6 6-3 6-4 7-6(3), to emerge the champion.
The top seed overwhelmed Britain's Cameron Norrie 2-6 6-3 6-2 6-4 in the second semifinal.
The top seed bounced back from two sets down to win 5-7 2-6 6-3 6-2 6-2.
The top seed crushed his fellow Serb 6-0 6-3 6-4 in the third round.
The top seed crushed the Australian 6-1 6-4 6-2 in their second round meeting.
He secured victory with an ace on his first match point and will next meet either Thanasi Kokkinakis of Australia or Poland's Kamil Majchrzak.
In an international career that spanned close to 23 years, Tendulkar went under the scalpel not less than three times – for problems ranging from tennis elbow to shoulder injury to the broken knee.