MELBOURNE, Australia (AP) - Novak Djokovic extended his winning streak to 27 matches and stayed on track for a fourth consecutive Australian Open title with a 6-3, 6-3, 7-5 win Friday over Denis Istomin.
Djokovic, whose last defeat came against Rafael Nadal in the U.S. Open final, is aiming to be the first player to win four Australian Open titles in a row in the Open Era.
He is looking the part, despite being broken in his first attempt to clinch the match Friday.
He's won all three matches so far in straight sets and his major threats - top-seeded Nadal, Andy Murray and Roger Federer - are in the other half of the draw.
Before rain cooled things off at Melbourne Park, Serena Williams persevered through a fourth day of searing temperatures to also advance.