Dozens of umbrellas went up at Jay Chou's concert on Saturday, as some fans had to contend with the rain coming in through a leaky roof at the Singapore Sports Hub.
They were disappointed that the retractable roof could not keep them dry.
Student Ken Leong, 22, said the organisers should have had contingency plans in place.
"Maybe they shouldn't have put seats in parts of the stadium where there was a risk of fans getting wet, like the area with no roof," he added, referring to the western end of the stadium.
Responding to queries from The New Paper, a spokesman for the Singapore Sports Hub said that water was seen dripping onto isolated areas of the stadium because of the heavy rain.
"We were immediately alerted to the situation and a task force was deployed to identify and assess the situation," the spokesman added.
"To ensure spectator experience was not impacted, the on-ground support team issued ponchos and relocated the affected patrons."
The Sports Hub also said it was looking into the issue and would provide further details at a later date.
This article was first published on December 30, 2014. Get The New Paper for more stories.