According to MSNbc.com Ellen Degeneres' first day on the American Idol judging panel didn't go very well.

The chat show host managed to 'lock horns' with Simon Cowell before she had got through a full day of judging.

Ellen's first day co-incided with Simon's Fox TCA press conference where he announced he was leaving the show. Simon ended up runnin late for his stint on Idol and Ellen was tres unimpressed. It looks like the happy one is a bit of a diva behind closed doors...

We already know Simon is a HUGE diva and was in a foul mood that day too. Can you imagine the atmosphere at that judging table?! Poor Randy and Kara.

We're glad we weren't auditioning for Idol that day...Cor!