Human Dominoes World Record
They were careful not to fall back and ruin the attempt before it even started.
The first volunteer, who was standing in front of an upright mattress and was coordinating the event by radio, told the other volunteers: "First of all, we need good teamwork.
"All the participants, from the first to the last, must act like one person, and that is dominoes.
"Then it must be accurate. The mattresses must be evenly arranged. It's one of the characteristics of dominoes."
The team leader, who was gripping his mattress with both hands, then fell backwards, knocking into the second person in the chain and starting the domino effect.
It was 10 minutes before the last one came down to finish the rally.
Crowds of onlookers cheered as the last volunteer standing was finally toppled over.
Guinness World Records authenticator Cheng Dong said careful planning had helped ensure the Shanghai team's success.
He said: "For an event like this involving 1,000 people to succeed first time is not just about luck.
All other conditions must be correct. First of all, all the participants must fully understand the rules.
"Second, our volunteers were all very brave. No one dodged when the two-metre-high mattress fell onto them. So the challenge was very successful."
The former holder of the Largest Human Mattress Dominoes record is La Quinta Inns & Suites in the United States.