Robredo pulled off the win of his career when he beat 16-time major winner Roger Federer in the fourth round at Flushing Meadows, but he couldn’t back it up against a rampant world No. 2 Rafael Nadal in the quarter finals with the Spaniard thumping him 6-0, 6-2, 6-2.
The other quarter-final played in New York on Wednesday pitted French eighth-seed Gasquet up against the fourth-seeded Spaniard David Ferrer, and it was the Frenchman who bounced back from losing the third and fourth sets to win 6-3, 6-1, 4-6, 2-6, 6-3.
That means that Nadal and Gasquet will now meet in a semi-final and if the Frenchman wants to reach the first Grand Slam final of his career he will need to beat the Spaniard for the first time in what will be their 11th meeting.
Nadal has won all 10 of his previous clashes with Gasquet including in straight-sets in the first round of the 2009 US Open.
Gasquet had already showed himself to be in terrific form at the US Open before his quarter-final with Ferrer having beaten American Michael Russell, Frenchman Stephane Robert, Russian Dmitry Tursunov and Canadian Milos Raonic.
He then took that confidence into the first two sets of the quarter-final firstly winning the first 6-3 and then dominating the second 6-1. In the second set, he played almost faultless tennis breaking Ferrer's serve three times and hitting an impressive 15 winners.
However, Ferrer wouldn’t have had the career that he has without having a huge heart and fighting spirit, and the world No. 4 hit back impressively to win the third and fourth sets to have all the momentum heading into the deciding fifth.
Gasquet steadied, though, and Ferrer perhaps tired a little from having to come back from two sets to love down and hit 11 unforced errors in the fifth set opposed to just three winners with the Frenchman able to take the set 6-3 to advance to the semi finals.
Gasquet had already broken through just by making the quarter finals having previously lost 14 of his 15 trips to Grand Slam fourth rounds.
He had previously only ever made it past the fourth round once, reaching the semi-final at the 2007 semi-final, so now by also entering the last four of the US Open it's just the second time he has been this far in his career and the first time in six years.
Without question, Gasquet has underperformed for his ability at Grand Slams during his career but now in the form of his life and with perhaps the best backhand in the game, the 27-year-old has every reason to think he can give it a real shot of beating Nadal for the first time.
Nadal, though, is in no mood for charity. If the Spaniard wins this year's US Open he will return to the world No. 1 ranking and it is going to take something special to stop him achieving that.
Robredo pulled off a stunning straight-sets win over Federer just to set up his quarter-final with Nadal, but the world No. 2 needed just an hour and 22 minutes to win through to the semi finals.
Nadal showed just how much he meant business in the first set. In just 22 minutes, he won it 6-0 allowing Robredo only five points in total for the set while helped by his opponent also hitting nine unforced errors.
While Robredo did get on the board winning four games over the last two sets, Nadal never looked like doing anything but win in an emphatic three sets.
In the end, it was an emphatic display by Nadal who didn’t hit a double-fault, hit 28 winners opposed to 15 unforced errors and incredibly won 15-of-16 points at the net.
Day 11 action at the US Open will now see the other two men's quarter finals take place starting with defending champion Andy Murray facing Stanislas Wawrinka. Then on the final match of the night on Arthur Ashe Stadium, world No. 1 Novak Djokovic takes on Russian Mikhail Youzhny.