Novak triumphed 6-3, 6-4 against no.3 seed Stefanos Tsitsipas to add the Kazakhstan trophy to victories in Rome, Wimbledon and Tel Aviv this season.
Novak and Daniil met for the 11th time in a highly anticipated semi-final match at the Astana Open on Saturday. The two players were level at one set apiece, 4-6, 7-6 (6), when the second seed decided to pull out due to a leg injury.
Novak Djokovic recorded a 6-3, 6-1 victory against world no. 34 Botic Van De Zandschulp on Thursday to advance into the last eight at the ATP 500 event in Astana, Kazakhstan. Number 4 seed will face Karen Khachanov (RUS) in the quarterfinals on Friday.
The 2010 champions will host 2015 title holders Great Britain in the Davis Cup by BNP Paribas World Group quarter-finals on July 15-17.