Nearly a month after blowing four match points as she threw away a 6-1, 5-1 lead at the US Open, the French number one Kristina Mladenovic underwent another Grand Slam tournament meltdown on Tuesday.
But instead of awarding the point to the 27-year-old Frenchwoman, the umpire, failing to see the double bounce, penalised her for touching the net.
Siegemund eventually held her serve to trail 2-5 on Court Philippe Chatrier.
Mladenovic then squandered the opportunity to claim the set 6-2 despite having another set point.
She racked up five more set points while Siegemund was serving at 3-5 down. But she still could not convert.
Siegemund eventually levelled as Mladenovic's game started to unravel and the 32-year-old German strode on to claim the opener 7-5.
"Kristina started solidly," Siegemund told the post-match interviewer Cedric Pioline. "I was making a lot of unforced errors but I tried to find my groove and cut down my mistakes and while I was doing that she made a few more errors."
A contest appeared plausible at the start of the second set when Mladenovic claimed Siegemund's serve to end the six game roll
But it was a fleeting fillip. Siegemund hit back immediately for 1-1 and she made the decisive break when Mladenovic was serving to level at 4-4.
Unlike her opponent, she did not fluff her lines at the crunch. "I played point by point," Siegemund added. "I tried to fix the errors and I wasn't thinking about the big picture. Even if I was down I was trying to see what the problem was and to fix it because it was only the first set and a long way to go."