Russian giant-killer Mikhail Youzhny delivered an awe-inspiring performance in a nail-biting third round match at the Arthur Ashe Stadium today and beat home favourite John Isner in four grinding sets to reach the pre-quarterfinals of the 2010 US Open, the season's last major being played here in New York, USA.

Re-live the excitement of this duel, click here.

Youzhny made a good start to the match and broke Isner early enough to close the opening set by 6 games to 4. The second set brought a much needed resistance from the American, who despite trailing by a double break, bounced back to win the set in a tie-break.

The third set witnessed continued brilliance from both players who tested each other to limits to once again push the set into a tie-break which Youzhny won by 7 points to 5. The fourth set brought a break in the third game for the Russian after which he carefully consolidated the lead with confident service holds and completed the 6-4, 6-7(7), 7-6(5), 6-4 win in three hours and 18 minutes of entertaining tennis.

Earlier in the day, Swiss Stanislas Wawrinka caused the biggest upset of the tournament so far when he knocked out this year's title favourite Andy Murray in four grinding sets. Murray made a bad start to the match but soon found rhythm to clinch the see-saw opening set in a tie-break. However, Wawrinka came all guns blazing to take the second set in a tie-break, followed by the next two sets with the help of a break each to complete the 6-7(3), 7-6(4), 6-3, 6-3 win in three hours and 56 minutes of play.

Wawrinka now meets American Sam Querrey who held off the challenge of Spaniard Nicolas Almagro 6-3, 6-4, 6-4 to make it to the last 16 of the event. Another Spaniard in the draw, who happens to be the world's best player currently, also made it to the next round. Eight time slam champion Rafael Nadal registered a confident 6-4, 6-4, 6-2 win over Frenchman Gilles Simon handily.

The day was definitely ruled by the Spaniards as veteran David Ferrer recorded a straight sets win over compatriot Daniel Gimeno-Traver, winning 7-6(2), 6-2, 6-2 to enter the pre-quarterfinals. Tommy Robredo also booked his last 16 berth after quite a struggle in the first three sets against Michael Llodra. The Frenchman eventually retired from the match due to an injury.  Inspired by his fellow countrymen, Spanish No.2 Fernando Verdasco  booked his place in the Round of 16 with a hard fought win over a resurgent Argentine David Nalbandian with a 6-2, 3-6, 6-3, 6-2 scoreline.

Verdasco's good friend, Feliciano Lopez turned out to be the last Spanish winner of the day when he moved ahead after his opponent, Ukrainian Sergiy Stakhovsky, retired mid way through the match, while trailing by a set and 0-4.