Two-time defending champion Aryna Sabalenka continued her imposing run at the US Open with a composed 6-3 6-4 victory over Kamilla Rakhimova in the third round on Friday, extending her bid for a fifth Grand Slam title.

Sabalenka opened play on a sweltering morning at Flushing Meadows and wasted little time making her intentions clear, breaking early to seize control and never looking back as she wrapped up the opening set.

"It's the first time I play morning session and it's a full stadium I'm so grateful, it's a dream," a smiling Sabalenka said on court.

The world number one unleashed her trademark power from the start, firing down a dominant serving display with four aces and dropping just four points on her first serve.

The only hitch for Sabalenka during the opener came when a strong smell of cannabis drifted on to the Louis Armstrong Stadium court, briefly disrupting play as she alerted umpire Eva Asderaki-Moore.

In the second set, Sabalenka found herself having to work harder for her holds as Rakhimova shook off the tension and made the top seed earn her way through her service games, while saving four break points of her own.

But Sabalenka eventually found the opening she needed, producing a blistering return to earn the decisive break before serving out the victory.

"She played incredible in the second set, push me so hard and motivate me to bring out my best," Sabalenka added. "I'm happy I closed this match in two sets."

Sabalenka, who has now won 16 straight matches at the US Open, is seeking to become the first woman since Serena Williams, who won three straight titles from 2012 to 2014, to complete a hat-trick of US Open crowns.

She will next face American Taylor Townsend, or Diana Shnaider in what would be a rematch of the French Open quarter-final match she lost against the Russian.