After rectifying his mistake and locating the correct woman, the 39-year-old passed the microphone over to the trembling husband-to-be.
"So for the past three years, thank you for your love," he said while fighting back tears.
"Thank you for giving me a chance. So in the midst of Coldplay, my new best friend Chris, and all the people here in Melbourne I just want to say I love you. Will you marry me?"
To the delight of the packed out arena and a smiling Martin, she said yes.
It wasn't the first time that a couple have got engaged in the midst of a Coldplay gig, with a British man popping the question as the band played Fix You at London's Wembley Stadium in June.
The sold-out Melbourne gig marked the second stop of the Australian leg of the band's A Head Full Of Dreams Tour.
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Suncorp Stadium in Brisbane hosted the opening concert before the band finishes off their Aussie stint with two gigs at Sydney's Allianz Stadium on Tuesday and Wednesday.
The mammoth 60-leg A Head Full Of Dreams tour began in Latin America in March and ends in North America in October next year.