Di Matteo repeated his mantra from last season's stunning upset of Barcelona ahead of Wednesday night's crunch showdown at Stamford Bridge.
The Italian had already billed the Group E game with Shakhtar as Chelsea's biggest since they were crowned kings of Europe, and he was under no illusions about the task facing his side against opponents who completely outplayed them in the reverse fixture two weeks ago to move three points clear at the top of the pool.
Admitting it was time his players played like European champions after taking just four points from their opening three matches, Di Matteo said: "We need to be at our best. We need a perfect game tomorrow night [Wednesday]. Every individual player going on the pitch has to perform at the highest of their ability.
"It's important we start well and get the crowd behind us and draw confidence from a good start."
Di Matteo said ahead of last season's semi-final triumph over Barca that Chelsea needed to produce two "perfect" performances.
Their 1-0 home victory over the defending champions was one of several they pulled out of the fire at Stamford Bridge, where they also delivered crucial wins over Napoli, Benfica and Valencia.
They need another such display to regain control of Group E, which they are in real danger of failing to get out of.
Di Matteo said: "There are some comparisons certainly to last season, when we had must-win games. Tomorrow [Wednesday] is another like that.
"Fortunately, we have players with the experience who have been through that before.
"We have to play the perfect game tomorrow [Wednesday] to beat Shakhtar, but we're strong at home. We've shown that over many years, and we'll be fired up for this game to win it."
Shakhtar have proven they are no pushovers though, and the Ukrainian side's boss Mircea Lucescu has warned Chelsea he is ready to mastermind another shock victory at Stamford Bridge.
Lucescu was the last manager to win a group game at the home of the Blues when Besiktas triumphed there in 2003.
"I prepare my players knowing very well that absolutely all the teams can be beaten, even Chelsea at home," said Lucescu.
Shakhtar's recent win over the European champions was their 17th victory in 18 games this season, their only blip being a 1-1 draw at Juventus.
They have also won a record 23 straight Premier League matches and have not been beaten competitively for almost a year.
The Ukrainians would appear to have all the tools to deal a near-fatal blow to the Champions League hopes of Di Matteo's men.
"For Chelsea, it's probably one of their last good chances to go through the group stage,'' Lucescu said.
"When you play in the championship in your country, you can actually undo your mistakes. But if you play in the Champions League, each loss is very important so you can't just undo it.
"Chelsea are a very strong team but we are not the weakest."