Sabalenka, Pegula maintain winning momentum at US Open

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.

The Belarusian 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.

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.

Elsewhere, Jessica Pegula kept alive her bid for a maiden Grand Slam title when the third-seeded American rallied from behind to beat fellow former US Open finalist Leylah Fernandez 1-6 6-4 6-3 and make the fourth round.

Pegula faces Sorana Cirstea in the last 16 and will need to iron out some of the flaws in her game after a sluggish start against Fernandez, but the she showed the resilience and composure that have made her one of the title contenders.

Romanian 16th seed Cirstea, 36, extended her impressive farewell-season campaign with a clinical 6-3 6-3 win over Italy's 19th-seeded Jasmine Paolini to reach the US Open fourth round for the first time in three years.

Ukrainian 11th seed Marta Kostyuk also kept alive her bid for a maiden Grand Slam title with a 6-3 6-2 victory over Russian Ekaterina Alexandrova in the third round.