Poyet watched his Black Cats side cap a thrilling come-from-behind victory over Jose Mourinho's Blues in the Capital One Cup quarter-final at the Stadium of Light on Tuesday night.
Lee Cattermole put through his own net early in the second half but Fabio Borini levelled in the 88th minute and Ki Sung-Yeung won the tie two minutes before the end of extra-time.
After the match, Poyet echoed Cattermole's assertion of the importance of the Premier League - and especially of Saturday's game at the Stadium of Light.
Poyet told Sky Sports: "That is massive.
"People ask me before, which one do you want to win? Both - I hope we can win on Saturday."
Of whether Tuesday's victory can be a turning point, the Uruguayan said: "I hope so.
"That was the idea we want, to maintain that consistency.
"They played fantastic, they didn't stop.
"They gave everything today and I hope they have turned the corner."
Poyet also wants his side to gain confidence from having beaten the title challengers Chelsea as well as Manchester City in November.
"That is fundamental," he added.
"It needs to be the platform to go on and win on Saturday.
"If we are like this, I think we can be a very difficult team to play."