Kristina Barrois and Anabel Medina Garrigues set up an unseeded women's final at the ATP-WTA Estoril Open on Friday before the skies opened to send men's top seed Robin Soderling and Juan Martin del Potro off court in their second set.
Del Potro, the 2009 US Open champion, had won the opening set but trailed 4-1 in the second when heavy rains arrived to interrupt afternoon play.
In an earlier quarter-final at the Estadio Nacionale, with Pablo Cuevas of Uruguay booked the first of the semi-final spots as he defeated Brazilian sixth seed Thomaz Bellucci 6-4, 6-2.
Matches featuring second seed Fernando Verdasco against South African Kevin Anderson and fourth seeded Frenchman Gilles Simon facing Canadian Milos Raonic had not started when the weather came.
On the women's side 29-year-old Barrois flew the flag for Germany as the 29-year-old reached the second final of her career, defeating Swede Johanna Larsson 7-6 (7/2), 6-4.
Barrois will aim to win her first title on Saturday against Spain's Medina Garrigues, who beat Monica Niculescu of Romania, 6-1, 6-3.
Barrois, a quarter-finalist last week in Stuttgart, said that her recent experiences in playing big matches and top players is boosting her confidence.
"I played some good matches last week in Stuttgart, they gave me the belief that I can face Top 5 players. I've been close against them but have not yet won. But I'm still working on it."
The German, ranked 71st, broke her Swedish opponent six times in a contest lasting one hour, 49 minutes.
Barrois beat Medina Garrigues in their only previous meeting, on clay at Strasbourg in 2009 when the Spaniard retired after losing the first set.
"I didn't have any special tactics in this win," said Barrois, losing finalist a year ago in Strasbourg to Maria Sharapova.
"I just stayed concentrated on all the points and tried to play steady.
"She's a good clay player and I had to fight for every point."
The 61st-ranked Medina Garrigues is playing for a title for the first time since 2009. The Spaniard owns nine career titles - eight have come on clay.
Medina Garrigues admitted she had a tough time in getting past Niculescu. "She makes you uncomfortable on court with her drop shots and high, fast balls. You have to run all the time.
"The result was more difficult than the scoreline, It was very tough, I was nervous at the start. But after she went ahead 2-0 I relaxed and started to play my game. I'm glad it was over in two sets."