It meant a delay to the much-awaited debut of Williams in Auckland. Her match was originally scheduled for 6.30 last night but has been pushed back to today.
Yesterday's events will add more fuel to the call for a roof over the ASB Tennis Centre, which has been discussed for almost a decade. Whether it is necessary or not is a moot point - Wimbledon, with all its money and the particularly fickle British climate - survived without one for decades and there are almost no tournaments at this level that have venues with a roof.
But the debate will continue, and might find favour among the frustrated punters that spent most of yesterday afternoon killing time, mostly in vain.
From the matches that were played, Czech Lucie Safarova gave a timely reminder of her class while Naomi Osaka justified all the talk about her potential.
Safarova, one of the forgotten women on the WTA tour, demolished Czech compatriot Denisa Allertova 6-1 6-2 in just over an hour.
Safarova, a former French Open champion, has been plagued by injuries in recent years, which has seen her ranking blow out to world No62. But the left hander showed signs of the form that has seen her as high as No5 and she will be a dark horse for the rest of the week.
Osaka (world No48) was also impressive, taking a 6-2 2-1 lead over German Annika Beck before the rain intervened.
The powerful Japanese looks like she could be a dangerous opponent in this tournament.
She demonstrated the class that saw her rise more than 150 places in the rankings last year, with some huge groundstrokes from both sides of the court.
In other matches, Kurumi Nara progressed easily past German wildcard Antonia Lottner (6-2 6-2).
Meanwhile, Barbora Stefkova (Czech Republic), Jamie Loeb (USA) and Mona Barthel (Germany) won through their final round qualifying matches.
Organisers now face a challenge to make up the time lost to the rain yesterday.
