WHATEVER happened, we were assured of some serious screeching and squealing at Wimbledon yesterday.

The combined decibel level produced by Maria Sharapova and her Portuguese opponent Michelle Larcher de Brito was such that canny visitors to Court No.2 made sure to pack ear plugs.

What no-one expected was that moaning and groaning about slippy conditions underfoot and occasional cries of agony would become the wider soundtrack to a remarkable day in the history of the All England Championships. Whether they had grounds for complaint or not, a day that witnessed a combined total of seven retirements or walkovers in both the men's and ladies singles draws ended with questions being asked about the suitability of the most famous grass courts in tennis.

While a statement from the All England Lawn Tennis Club pointed to independent evidence that demonstrated the courts were "almost identical" to 12 months ago, it was perhaps unsurprising that the chorus of outrage should be led by Viktoria Azarenka and Maria Sharapova. The Belarusian world No.2 had started the tidal wave of withdrawals by handing Flavia Pennetta a walkover after suffering bruising to a knee bone in a first-round fall on Monday. Sharapova, on the other hand, soldiered on to the end of a 6-3, 6-4 loss to Michelle Larcher de Brito, but fell no fewer than three times, required a lengthy injury time-out, and was overheard complaining to the umpire that the court conditions were dangerous.

"I buckled my knee three times, and I've just never fallen that many times in a match before," Sharapova said, even if the only damage sustained was a strained muscle near the hip and the embarrassment of flashing her orange knickers. "I have noticed a few more players falling a bit more than usual. In the first couple of days, the courts are always a bit like that, but I don't think I've seen as much as this."

Azarenka was also left passing on recommendations to the ground staff. "The court was not in a very good condition," she said. "My opponent fell twice, I fell badly and there were some other people who fell after. I think there might be a cause – something that could be looked into in the future. I don't know if it's the court or the weather. I can't figure it out it. It would be great if the club or somebody who takes care of the court just would examine or try to find an issue so that wouldn't happen. Because there is nothing I've done wrong which has caused me to withdraw."

Sharapova's impressive Portuguese opponent at least had the good grace to sympathise with her vaunted opponent. "From what I felt, there was like dead grass on the top, and that made it quite slippery," she said. "But I just tried to be more careful."

After Yaroslava Shvedova of Kazakhstan handed 2011 champion Petra Kvitova a walkover when she pulled out with an arm injury, Caroline Wozniacki, the No.9 seed, suggested the grass may have been longer than usual after aggravating an Achilles tendon problem during her 6-2, 6-2 defeat to Petra Cetkovska. "It's just not fun to be out there when you feel you can't really push off on your foot," the Dane said.

Seeds were also dropping like flies in the men's draw, even if a few different theories were being put forward. Of two potential quarter final opponents for Andy Murray, No.6 seed Jo-Wilfried Tsonga was unable to finish against Ernests Gulbis, and No.10 seed Marin Cilic was unable to start. Giant John Isner crashed to earth seriously enough to forfeit his match with Adrian Mannarino, while Radek Stepanek was unable to finish his encounter with another monster in the men's draw, Jerzy Janowicz.

Tsonga, who was trailing 6-3, 3-6, 3-6 to Latvia's Gulbis when he threw in the towel, complained of tendinitis in his knee but suggested the cool weather might have been to blame. "No, there is nothing about this court," Tsonga insisted. "They are great. The only thing we can say is the weather we have had for a couple of weeks. For myself, you know, the weather is not that good to play tennis because it's cold outside, and it's humid. For all the joints, it's not really good."

Cilic raged at an ongoing knee problem which flared up during his recent run to the final at Queen's. "Last week I was feeling it already," the Croat said. "After three sets on Monday I felt it much, much worse. It was difficult for me to put weight on my left leg, which is where the pain is. So I had basically no choice."

Considering the abandon with which he deliberately threw himself onto them, one man who couldn't blame the courts was Belgium's Steve Darcis. Heartbreakingly, the world No.135 was unable to bask in the spoils of his first-round win over Rafael Nadal due to a shoulder problem, the same joint infamously emblazoned with a tattoo of a shark. "It happened in the middle of the first set," Darcis said. "When you beat a guy like Rafa you want to play more. But to not to go on the court is maybe the most disappointing thing I have ever had to do."

The intrigue about the Wimbledon grass may never be resolved but the events of yesterday were the equivalent of someone taking a Flymo through both singles draws.