After 10 days of clear weather, rain and winds swept through Flushing Meadows Thursday, tossing the US Open's final weekend into disarray and stranding Rafael Nadal and Fernando Gonzalez in the midst of their quarter-final.
For the second year running, Nadal faces the prospect of playing a string of successive days at the year's last major if he is to win the only grand slam missing from his collection.
Nadal was leading Gonzalez 7-6 6-6 with the Chilean serving at 2-3 in the tiebreak when a second shower burst halted Day 11 proceedings at Arthur Ashe Stadium.
The eventual winner of the last men's quarter-final will meet Argentine Juan Martin del Potro, who had battled through blustery conditions to beat Croatian 16th seed Marin Cilic 4-6 6-3 6-2 6-1.
Nadal and Gonzalez will resume their battle no earlier than 1400 (1800GMT) today following the first women's semi-final pitting champion Serena Williams against Kim Clijsters.
The semi-final between Caroline Wozniacki of Denmark and Belgian Yanina Wickmayer will follow the men's contest.
A year after Nadal's semi-final against eventual runner-up Andy Murray spilled into a second day because of the remnants of Tropical Storm Hanna, the Spaniard again ran into foul weather.
Nadal, his groundstroke drives piercing through the swirling winds, lost just one point on his serve until the 11th game when he had to fend off two set points to stretch it into a tiebreaker.
After winning the tiebreak 7-4, Nadal took timeout to have a trainer treat his strained abdominal muscle before beginning the second set.
They managed to play only four more games when a cold drizzle forced the first interruption of the match.
"In the first set it (the abdominal strain) was very very bad," Nadal's uncle and coach Toni Nadal told reporters.
Seventy-five minutes later they returned to a three-quarter-full stadium where the temperature had considerably dipped and gusting winds swirled through centre court.
Nadal was on the verge of clinching the second set in the 10th game. Gonzalez saved two set points with service winners, but the Spaniard appeared ready to pounce on his third when flying debris caused the umpire to halt play in mid-point.
As Nadal pumped his fist in disgust, the umpire announced to the crowd: "Ladies and gentlemen, will you please make sure you don't leave any napkins or plastic bags around."
The 11th-seeded Chilean saved the replayed set point with a forehand winner and took the second set into another tiebreak.
Seconds later, the players were sent back to the locker room again. After hanging around for nearly two more hours until just after midnight, organisers sent everyone home.
While Nadal and Gonzalez faced an anxious night, Del Potro was already celebrating his second grand slam semi-final of the year.
Fighting back after losing the first set and trailing 3-1 in the second, the Argentine induced Cilic into a flood of groundstroke errors and the demoralised Croat lost 17 of the final 20 games.
Cilic had 53 unforced errors in all, compared to just 24 for Del Potro.
"My dream is to win this tournament," said the soft-spoken Argentine, who also reached this year's French Open semis.
"It's my favorite surface, the biggest stadium. Many Argentines come here to see the match. So for me, it's the best one."
Five-times champion Roger Federer and fourth seed Novak Djokovic will contest the other semi-final of the year's final grand slam tournament.