Former champion Svetlana Kuznetsova moved smoothly into the US Open quarterfinals on Monday, profitting from a bottom half of the women's draw that has been blown wide open.
The 22-year-old Russian, who was an upset US Open winner in 2004, defeated fast-rising 18-year-old Victoria Azarenka of Belarus 6-2, 6-3.
Next up is another 18-year-old in the shape of Agnes Szavay of Hungary, who defeated Julia Vakulenko of Ukraine 6-4, 7-6 (7/1) in another early fourth-round tie.
Kuznetsova is the highest-ranking player left in a lopsided lower section of the draw which has seen the early departures of defending champion and second seed Maria Sharapova and seventh seed Nadia Petrova, both Russians.
In contrast, the top half contains most of the big names with the quarter-finals already set opposing top seed Justine Henin against Serena Williams and third seed Jelena Jankovic against Venus Williams.
Kuznetsova, one of the most consistent players on the WTA Tour this year, had little to do in the first set as Azarenko dug her own grave by spraying her groundstrokes wide and long.
Azarenko started to find her touch to break the Russian's serve at the start of the second set, but Kuznetsova replied by stepping up her own game to level.
The Russian then cracked a crosscourt forehand winner to break for a second time in the eighth game of the set
A nervy Kuznetsova let four match points get away on her serve in the following game, but converted at the fifth attempt with a deft serve and volley.
Szavay, who has emerged only in the last few months with a WTA tournament win in Palermo, was the more solid in a tight first set against Vakulenko, who at 24 was by far the oldest player left in the bottom half of the draw.
Both players though struggled to hold on to their serves in the second set which went into a tie-break.
Vakulenko won the first point in that but then Svazay reeled off seven points in a row to reach the last eight in what is only her third appearance in a Grand Slam tournament.
The two remaining fourth-round ties on Monday see Israeli 18th seed Shahar Peer going up against Sharapova's conquerer, Agnieszka Radwanska of Poland, and Russian sixth seed Anna Chakvetadze opening the night session against 16-year-old Austrian prodigy Tamira Paszek.