The world No. 2 men's and women's players both exited the US Open in New York on Friday as Peter Norfolk took pole position in the round-robin phase of the quad singles event.
Stephane Houdet of France ended Dutchman Maikel Scheffers' hopes of a second Grand Slam title of the season as the world No. 3 and world No. 2 met in the semifinals of the men's singles.
But for the second successive week in the USA, Roland Garros champion Scheffers was unable to find his best form as Houdet snatched the opening set 6-4 in 30 minutes and then swept through the second set to secure a 64 60 victory.
After losing his Roland Garros title to Scheffers in June, Japan's world No. 1 Shingo Kunieda continued in imperious form in New York as he kept up his US Open title defence with a routine semifinal victory. Kunieda dropped just two games against games world No. 7 Ronald Vink of the Netherlands, rounding off a comprehensive 62 60 victory by breaking Vink's serve to love and sealing the second set in just under 30 minutes.
Van Koot powers past Griffioen
World No. 2 Jiske Griffioen arrived in New York having been beaten by her fellow Dutchwomen Esther Vergeer and Marjolein Buis in the semifinals at the Australian Open and Roland Garros and her quest for a place in the last Grand Slam final of 2011 was against thwarted on Friday by another of her compatriots.
Aniek van Koot was edged out by Griffioen in two extremely tight sets in the semifinals of the last Super Series event of the season in St. Louis last week, but world No. 4 van Koot stamped her dominance in their semifinal in New York from the outset as she opened up a 3-0 first set lead.
Van Koot managed to maintain her three game cushion over Griffioen as she took the first set and then won four games in succession in the middle of the second set en route to wrapping up a 63 62 victory.
Unsurprisingly, van Koot will play Vergeer in the women's final after the world No. 1 held off a determined challenge from Belgium's Annick Sevenans. Vergeer raced in to a 4-0 lead in her semifinal before taking the opening set 6-2 in 26 minutes, but Sevenans managed to come from 3-0 down in the second set to move to within a game of Vergeer at 3-2.
Sevenans then denied Vergeer the opportunity to serve out the match at 5-2 up as the Belgian broke the Dutch serve. However, after the players split the first four points of the next game in equal measure Vergeer earned her one and only match point, which was converted to seal a 62 63 victory.
Norfolk tops quad round-robin pool after the second day
This week's world No. 1 David Wagner and world No. 2 Peter Norfolk have fought out all three US Open quad singles finals that have been played since 2007 and the likelihood of a repeat increased on Friday as both players gained straight sets victories in the second set of round-robin matches.
On the back of a scintillating straight sets win over Wagner on his Grand Slam debut on Thursday, world No. 3 Noam Gershony of Israel looked set to cause another upset as he took an early 3-0 lead over Norfolk on Friday.
Gershony looked poised to take the opening set as he served out a love service game to make it 5-3, but having beaten Gershony for the loss of just two games in St. Louis, Norfolk's vast experience helped him find a way to string together four games in a row and he finally edged the set.
Norfolk ended a sequence of four successive service breaks as he took a 3-2 second set lead and went on to take the last four games of the match to complete a 75 62 victory.
In the day's other quad match Wagner needed just 19 minutes to wrap up the first set against his fellow American Nick Taylor.
Taylor had opportunities to keep within a game of Wagner in the second set, but could not takes his chances in a tight third game and Wagner moved 3-0 ahead en route to finally completing a dominant 60 62 win that leaves plenty to play for in Saturday's final set of round-robin matches, when the American takes on Norfolk.
Gershony plays Taylor, with the possibility of the group phase of the competition ending with three players on two wins apiece.
Top seeds progress to doubles finals
Saturday's scheduled penultimate day of wheelchair tennis action in New York will see all three doubles finals take place after the top two seeded partnerships emerged victorious from Friday's semifinals.
Australian Open and Wimbledon champions Scheffers and Vink remain on course in their US Open title defence after a tough three set semifinal against Kunieda and American former world No. 1 and Paralympic doubles medallist Stephen Welch.
Kunieda and Welch threatened to derail the Dutch top seeds after streaking through the second set for the loss of just one game, but Scheffers and Vink clawed back the advantage to seal a 64 16 62 victory.
Nicolas Peifer has also reached the men's doubles final for the second successive year after partnering his fellow Frenchman Houdet to a 63 63 victory over the Roland Garros runners-up and 2010 Wimbledon champions, Dutchman Robin Ammerlaan and Stefan Olsson of Sweden. Houdet and Peifer earned a 63 63 victory.
There will be an all-Dutch women's doubles Grand Slam final for the fourth time in 2011 after second seeds Griffioen and van Koot made a fine recovery from 6-1 down in the second set tiebreak of their semifinal against their countrywoman Marjolein Buis and Sevenans.
Buis and Sevenans looked like taking Griffioen and van Koot to a third set as they established a commanding advantage in the tiebreak, but the second seeds were havng none of it and eventually pulled through 64 76(8) for a hard-won victory.
In the other semifinal American wild card entry Emmy Kaiser and Australia's Daniela di Toro also pushed top seeds Vergeer and Sharon Walraven in the second set of their semifinal. But this time there was to be no tiebreak as defending champions Vergeer and Walraven kept themselves on course to win all four Grand Slam titles in the same year for the first time after clinching a 62 75 win.
Saturday's schedule will also see Norfolk and Gershony play defending champions Taylor and Wagner in the quad doubles final.
US Open Grand Slam Draws
US Open Schedule - Saturday 10 September
Gershony beats Wagner in New York