"That's… amazing," Porter added.
Meanwhile, presenter Bradley Walsh looked confused.
"Well that's, that's different," a red-faced chaser replied.
"Whatever happens you've accomplished two things that no other contestant ever has," Anne Hegerty told the actress. "You've embarrassed me, and you've made Bradley look tall."
However, that wasn't the end of the awkwardness.
Things got heated up during the questions.
Asked a question about actor Steve Martin, Lucy was excited about knowing the answer that she hit "B" before the host had finished reading out the options.
"Did you press that button?" Walsh asked her.
"I tell you something now," he continued. "I don't care how much you love him more than me, you cannot press the button until I've finished reading the question!"
Porter didn't seem too bothered and the host took her aside for a hilarious warning.
"I'm the one who says what you put, you don't press the button before I have finished the question," he told her.
"Don't come and try and run the show, we are going to fall out my dear," he continued, while the audience laughed away.
The Chaser revealed she didn't know the answer but guessed it because she saw how sure Porter was of her own answer.
"I didn't know that…" Anne said. "Let's just say it was quite obvious that you knew it was B."
"Hold everything! What have I missed?" the host asked.
"You're ruining my show you are!"
In the end, the celebrity line-up managed to beat the chaser and win more than $150,000 to donate to their chosen charities.
