Roberto Di Matteo watched his attacking stars inspire a 5-4 extra-time victory over Manchester United and he preferred to savour a second night of high-scoring league cup thrills rather than focus on "the other stuff" in football.

The Chelsea manager did not need to spell out what he meant, in the wake of the league fixture against United on Sunday, when his team's controversial 3-2 home defeat was followed by the allegation that the referee Mark Clattenburg had racially abused Mikel John Obi. There had also been spite in the stands.

Di Matteo focused on the flair and spirit that his team had shown here, when they came from behind three times to force the extra period, with the substitute Eden Hazard scoring from the penalty spot with the very last kick of normal time. Hazard's quick feet and sumptuous reverse pass created what proved to be the decisive fifth goal late in extra-time for Ramires.

"Over the last two days we have seen some exciting, thrilling football," Di Matteo said, with a nod towards Arsenal's 7-5 Capital One Cup win at Reading on Tuesday. "We have seen a lot of future stars and that's what we should promote and not the other stuff. We showed a big heart, passion and pride not to lose."

Chelsea have been drawn at Leeds United in the quarter-finals, which Di Matteo admitted would be a night for his players to show their "fighting spirit", but also one which would bring a happy reunion for him. "Ken Bates [the Leeds chairman] was the person who signed me when he was at Chelsea," Di Matteo said. "I have fond memories of successful times with him. He was always very good to me, him and his wife Susannah."

Sir Alex Ferguson watched Ryan Giggs, one month shy of his 39th birthday, last the 120 minutes and score twice, the second a penalty at the death which hinted, briefly, at another remarkable comeback. "He's an example to every player on the pitch, including the Chelsea players," the United manager said.

Ferguson was left to lament a lapse by Nani, who lost possession, leading to Chelsea winning Hazard's last-gasp penalty while he admitted that his young centre-backs, Scott Wootton and Michael Keane, had suffered towards the end. Wootton conceded the penalty for Hazard while his botched back-header allowed Daniel Sturridge to put Chelsea 4-3 up.

Di Matteo was not overwhelmed by the joys of the night. He wondered why Keane had not been penalised for handball, as Chelsea trailed 3-2 and he grumbled again about Fernando Torres' sending-off in the league fixture on Sunday. "It's incredible that it always hits Chelsea football club and that's maybe something to think about," he said. "We would just like to be treated fairly. By everybody."

Di Matteo was asked, in the wake of Chelsea's allegations against Clattenburg, whether he feared that referees might victimise his team. "No, the referees should be going into the games with the most confidence," he said.