The pair discussed the heat rule that says a female competitor can take a 10 minute break between the second and third sets if the temperature rises over 30.1 degrees, but it did not end friendly.
"The most glaring example of rampant sexism I've ever seen," Piers called the ruling.
He began to say that he was "looking forward to feminists marching…" before being interrupted by his co-host.
The brunette beauty, 46, exclaimed: "It's the men who need to march. You're always worried about these things!"
Sean Fletcher discussed the rule with Piers and Susanna
Piers and Susanna began a fierce debate about the ruling
Why do we have to fight your battles for you?
However, things became heated after Piers, 52, suggested that feminists should march through Wimbledon in protest over the ruling that doesn't apply to men.
Susanna demanded to know why it had to be women who marched, to which her co-host replied that they're about equality.
Piers explained: "The women have an unfair right and that should be removed. We should all be exactly the same."
"Why do we have to fight your battles for you?" Susanna demanded to know.
Piers Morgan's most famous Twitter spats Thu, September 22, 2016
Good Morning Britain host, Piers Morgan's most outrageous quotes and Twitter spats.
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Piers Morgan's most outrageous quotes
She continued: "Oh I see you want women to march to lose a right in order to be equal with the men?
"We've got enough work to do fighting our own battles," Susanna concluded.
This come after Piers launched a fresh attack on BBC Breakfast over their "falling ratings" earlier in the show.