The backing dancers' strapless costumes and polka-dot miniskirts also stunned the audience in China at a time when people still dressed in similar shades of green and gray.
"It was the first time a Western band had come to China. Everyone was ready to make some noise and stand," said Li Ji, a restaurant owner who went to the concert in his 20s. "But there were so many police officers there, people didn't dare to."
Wham!'s manager Simon Napier-Bell had spent 18 months persuading the Chinese government to let the band in and secure their place as one of the world's biggest acts by telling officials it would help attract foreign investment.
The police had warned spectators to stay seated, worried that they would be unable to control the crowds and that there might even be riots. Some young Chinese who got up to dance were hauled away by security officers.
The Wham! concert influenced Chinese musicians, who had never seen electric guitars played on stage and began to get interested in rock 'n' roll.
Huang Wen, a music writer, said the performance had an impact on big-name musicians, including the godfather of Chinese rock, Cui Jian.
"In the early 1980s, pop songs from Hong Kong were very popular in mainland China, and after the concert college students and people in the music industry started to get interested in rock 'n' roll," she said.
Li said the army department his parents worked for had given out tickets as a benefit. He attended the concert with his parents' colleagues and their kids.
"I remember there was a little incident during the concert, the main lights went out because there was a problem with the electricity, so the bassist danced a little break dance," Li said. "It was the first time people saw that, and it was so popular, people liked it."
State media said Monday that the concert "was a sensation." While young Chinese today don't know the names George Michael or Wham!, many instantly recognize his well-loved songs "Last Christmas" and "Careless Whisper."
The latter had already been translated into Chinese and sung in several versions before the 1985 concert.