New York - Around 20 000 people watched it rain on the Arthur Ashe Stadium on Wednesday but only Kei Nishikori was happy to see it as the brief shower shut the roof and slammed the door on Andy Murray's US Open.
Over a dramatic four hours, Japanese sixth seed Nishikori recovered from two sets to one down and a potentially fatal break point to triumph 1-6, 6-4, 4-6, 6-1, 7-5 and reach the semi-finals for the second time.
In a match of thrilling momentum shifts, it was Nishikori who thrived on the two key turning points.
First, a few afternoon showers saw the $150 million roof shut at 3-3 in the second set, slowing the conditions enough for his long-term benefit.
Then, with Murray on the verge of a break for a 3-1 lead in the fourth set, the stadium's sound system burst briefly into life.
The point was replayed, Murray lost the plot and the scene was set for a titanic fifth set which saw five breaks of serve in a match featuring 17 such breaches.
Nishikori admitted the delay in play, which allowed for the roof to close, allowed him and his coaches Michael Chang and Dante Bottini to discuss a new approach.
"It was definitely my mistake that I lost the first set. I was missing too much. I was feeling a little bit rushed. I gave so many opportunities," said the 26-year-old who was broken in the fourth and sixth games of the opening set.
"But we talked a lot of things during the rain delay, and I tried to change something. It worked well. For sure it helped today's game."
Murray, not surprisingly, was aggrieved that the roof was closed for the rest of the match.
Once the brief showers had passed, the skies of New York reverted to their September default - sunny, hot and humid.
"We were told at the beginning of the event and also today that if the forecast's good they will open the roof during the match. Why that didn't happen today I don't know," said the 2012 champion.
"Under the roof he was able to dictate more of the points. He was playing a bit closer to the baseline than me and taking the ball on a little bit more."
Murray also carried on a long-running monologue over what he saw as the injustice of having the crucial break point at 1-1 in the fourth set replayed when the faulty sound system blasted out a brief gong-like sound.
As he raged, seven games on the bounce slipped past him and Nishikori was back in the match.
The Japanese star believes umpire Marija Cicak was right to halt play.
"My concentration went off. I don't know what's the reason, but for sure they have to stop that," said Nishikori.
Having finished runner-up to Marin Cilic in the 2014 final in New York, Nishikori will now face Stan Wawrinka for a place in Sunday's championship match.