Nole opened his Dubai Duty Free Tennis Championships campaign with a 6-1, 6-4 win over Viktor Troicki and set up second round match against Spaniard Roberto Bautista Agut.
Defending champion is through to the second round of the Australian Open with a comfortable 6-2, 6-4, 7-5 win over Frenchman Paul-Henri Mathieu in 1 hour and 42 minutes.
Novak opened his 2012 China Open campaign with a 6-1, 6-7(3), 6-2 win over German qualifier Michael Berrer.
World no.2 opened his US Open title defence campaign with a convincing 6-1, 6-0, 6-1 victory over no.69-ranked Italian Paolo Lorenzi in just 73 minutes.
World no.1 defeated Potito Starace in straight sets 7-6(3), 6-3,
6-1 to advance into second round of the French Open.