Summer signing Darren Bent continued his impressive start to life with the Black Cats with the opening goal totally against the run of play in the 18th minute.
But strikes after the break from Michael Ballack, Frank Lampard and Deco saw Carlo Ancelotti's side cruise to a 3-1 success after dominating throughout.
Bruce could not fault his players for their efforts and admitted they were simply beaten by a superior side, but felt the recent international action had not helped his team as they chased and harried in an attempt to preserve their slender advantage.
He told Sky Sports: "They have put on one hell of a show. That's as impressive as I've seen Chelsea play. Whatever we tried to do to match their system, we just couldn't get to grips with how we were going to stop them.
"We were valiant and we tried hard and in the first half we made a fist of it. But the longer it goes the energy levels from the internationals a week ago catch up with you.
"We haven't got that energy to keep after them. But you have to sometimes admit that we were beaten by a very, very good team tonight. You have to hold you hands up and say well done to Chelsea."
Very bestBruce praised Bent for his clinical finish from the rare chance Sunderland created but felt his side were always going to be up against it as they tackled the Stamford Bridge superpower.
He said: "That was possibly our only chance and we took it. Darren showed what a great acquisition he will be for us, he was tireless all night.
"It was a difficult night for us and we have to admit that. It was a very, very good Chelsea performance.
"That's why they're competing with the very best, they are as good as they come. They are as good a team as there is in Europe and tonight they showed it.
"We stuck at it and stuck with them for a good hour, but after that they ran out easy winners.
"We are not going to come up against teams like that very often, but that's what we all aspire to. That's why they are at the top of the league and why they win Premier Leagues and compete for European championships.
"They are a class act and they showed it tonight."