The blonde presenter played a clip of her co-host presenting at the 1984 New Zealand Music Awards for viewers on the ITV show, despite him begging she didn't in the background. But she merely shushed him, and proceeded to get a still of him on her phone.
"There he is," she laughed, before a contrasting picture of Thunderbirds character Brains flashed up, which was enough to have the pair doubled over in the studio.
The 36-year-old model and TV presenter also couldn't stop giggling when she read out some of the Twitter responses to the nostalgic snap of Phillip.
"Honestly you lot are brilliant. People said: 'Oh we all had hair like that in the eighties," someone said: "He looks like Brains, how high is his hair!'"
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Phillip Schofield was at the mercy of his co-presenter on This Morning
Phillip was embarrassed when Holly pulled out a throwback picture
The still of Phillip presenting at the New Zealand Music Awards in 1984
As they continued to laugh over the comparison, Phillip appeared to give in at that point, saying: "All right, you win."
But, the 55-year-old had something else up his sleeve, as he immediately got out his phone and tweeted a grumpy message to his co-host.
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"And that's what I'm going to tweet to you."
Holly looked over his shoulder and gasped in shock, before chastising her colleague: "I just read that – you can't read that out."
Holly Willoughby in pictures Wed, June 7, 2017
This Morning host Holly Willoughby in pictures.
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Holly Willoughby in pictures
The pair have presented together since 2005
Phillip looked utterly shocked at Holly's teasing
"I can't read it out but I've just posted it, there you go," he answered.
Shocked, Holly turned back towards the audience in indignation: "How rude!"
The Oldham presenter had posted: "You utter s****! Love from Brains."
"Charming," Holly added.