NEW YORK, USA (AFP) — Rafael Nadal and Roger Federer cruised into the fourth round of the US Open on Saturday, taking a crucial step toward a possible first-ever Grand Slam matchup on the Flushing Meadows hardcourts.

And the last-16 roadblocks to their potential quarter-final showdown at Arthur Ashe Stadium are a combined 1-19 in their respective personal matchups against the superstar duo.

Spanish second seed Nadal, a 12-time Grand Slam champion, stretched his career-best hardcourt win streak to 18 matches by beating 38th-ranked Croatian Ivan Dodig, 6-4, 6-3, 6-3.

Federer, seeking his 18th Grand Slam title and sixth US Open crown, fired eight aces and 34 winners in defeating 63rd-ranked French left-hander Adrian Mannarino 6-3, 6-0, 6-2.

On the women’s side, two-time Australian Open champion Victoria Azarenka advanced in three sets and Daniela Hantuchova saved four match points to reach the last 16, but Grand Slam winners Petra Kvitova and Svetlana Kuznetsova and former world number one Caroline Wozniacki were beaten.

Next up for Federer, in his lowest Grand Slam seeding since 2002 at seventh, will be Spanish 19th seed Tommy Robredo, who has lost all 10 matches he has played against the Swiss star, the past four in Grand Slams.

Nadal, who completed a career Grand Slam with his 2010 US Open crown but missed last year’s Open with knee injuries, has won nine titles since returning in February from a seven-month layoff.

Nadal, who is 56-3 this year and has held serve 37 times without fail over three matches, took command early, connecting on 65 per cent of his first serves and 37 winners.

Next up for Nadal will be 22nd seed Philipp Kohlschreiber, who ousted US 13th seed John Isner.

Nadal is 9-1 against the German, losing only last year on Halle grass and winning their most recent meeting at Monte Carlo in April.

Azarenka, who lost to Serena Williams in last year’s final, outlasted French 26th seed Alize Cornet 6-7 (2/7), 6-3, 6-2.

Next up for Azarenka will be Serbian 13th seed Ana Ivanovic, the 2008 French Open champion who edged Christina McHale 4-6, 7-5, 6-4.

Italian 21-year-old qualifier Camila Giorgi, ranked 136th in the world, stunned Danish sixth seed Wozniacki 4-6, 6-4, 6-3.

Next for Giorgi is 10th-seeded compatriot Roberta Vinci, who eliminated Italian Karin Knapp 6-4, 6-3.

Czech seventh seed Kvitova, the 2011 Wimbledon champion diagnosed with a virus Friday, made 27 unforced errors and seven double faults in losing to 81st-ranked US wild card Alison Riske 6-3, 6-0.

Riske next faces 48th-ranked Slovak Hantuchova, who struggled with a sore right shoulder but beat Israeli qualifier Julia Glushko 3-6, 7-5, 7-6 (7/4).

Russian 27th seed Kuznetsova, the 2004 US Open and 2009 French Open champion, made 35 unforced errors in losing 7-5, 6-1 to Italy’s 83rd-ranked Flavia Pennetta.

Pennetta will next face Romania’s Simona Halep, who reached her first Slam last 16 by ripping Russian 14th seed Maria Kirilenko 6-1, 6-0.