The elder statesman of the Chelsea line-up -- 34-year-old Didier Drogba -- scored the winner as the Premier League side withstood a furious Barcelona onslaught to hang on for a memorable first-leg victory.
Chelsea's win came despite being outplayed by long periods, with Barcelona enjoying 72 percent possession throughout the match to their opponents' 28.
The Spaniards also had 24 attempts on goal while Chelsea's only shot on target came in the shape of Drogba's winner.
Nevertheless the win was a triumph for Drogba, Frank Lampard, John Terry, Ashley Cole and Petr Cech as Barcelona were sent crashing to their first European defeat this season.
"In the past a lot of the public opinion has been that these boys are over the line and too old to play two games at this level," Di Matteo told reporters, referring to Chelsea's FA Cup semi-final win over Tottenham on Sunday.
"It wasn't just (Drogba) -- we had other players on the pitch that you regard as old guard that have played two games in such a short period of time. I think they gave their answer on the pitch tonight."
Di Matteo had surprised many pundits by electing to start with Drogba in attack ahead of £50 million man Fernando Torres.
However the interim Chelsea manager admitted he had chosen Drogba to start after being impressed by his goalscoring contribution to Sunday's 5-1 drubbing of Spurs at Wembley.
"I felt I had to be fair looking back at the game on Sunday with the way we wanted to play. For today's game he was the right man to play," Di Matteo said.
While praising the veterans of Chelsea's line-up, Di Matteo was at pains to pay tribute to a "tremendous" collective effort.
"I think that the balance has to be good within the team. It's not just the defenders defending -- it's the whole team," Di Matteo said.
"So I think you need to be able to close down the space as much as possible and limit their threat as much as possible. But ultimately with the quality of the individuals they have they will create some problems.
"But it wasn't just our defenders it was a collective defensive performance.
"We're delighted with the performance of the team and the result we got today. We've won all our Champions League games at home this season and we've faced some tough opponents.
"I think tonight was one of the biggest challenges we've had for many years."
Barcelona coach Pep Guardiola meanwhile said the defeat had left Chelsea as favourites to advance to next month's final in Munich.
"They are favourites," Guardiola said. "They have a good result but at least we have the challenge to play 90 minutes. And in that time we have the opportunity to create chances. But 1-0 is a very good result for them."
Di Matteo brushed off Guardiola's assessment of the tie however.
"I don't think it makes us favourites," he said. "It's 50-50 for both teams to go through to the final.
"You know what to expect when you go to the Camp Nou -- it's going to be very very difficult. We still have to believe that we might be able to score a goal there. It's going to be a tough game, it's a tough game for anyone going there.
"We'll have to be at our best again. We're very pleased but it's only half-time and nothing has been decided. We've another game to play yet."
Guardiola meanwhile dismissed suggestions that Barcelona had been robbed of victory given their overwhelming dominance of possession and shots on goal.
"They won, that's football," Guardiola said. "It's not a question of fairness. They scored, and we didn't. Congratulations Chelsea.
"If football matches were awarded to teams who had the most average possession of the ball we would win every game. But the most difficult thing is getting the ball into the net."
Source: AFP
Source: AFP