Few could have expected the impact the Italian assistant has had, after guiding the Blues to four consecutive victories since replacing Andre Villas-Boas at the west London helm.
After successfully steering the club through their FA Cup fifth round replay at Birmingham City, Chelsea beat Stoke 1-0 in the Premier League and then overcame the odds by progressing to the Champions League quarter-finals at the expense of Napoli in a thrilling European encounter in midweek.
Following the gruelling game last Wednesday, Chelsea hosted Championship side Leicester City, and after recording another impressive 5-2 victory, the Blues have set up an FA Cup semi-final clash against either Tottenham or Bolton.
"I'm very pleased, it was a wonderful team performance which was reflected in the scoreline, everybody was happy today, we had a good game, we won and we're in the next round," Di Matteo told the club's official website. "We wanted to get to the next stage and I thought we did it very well.
"We're just happy we've managed to overcome every hurdle so far, but you don't have time to enjoy the wins because we're playing on Wednesday and then Saturday again, but we're happy we're in the semi-final and now we're focusing on Manchester City."
Di Matteo made seven changes to the side that started against Napoli, with Fernando Torres restored to the forward line. It was a decision that made quite an impact as the Spanish striker bagged a brace and turned provider for two other Chelsea goals.
"The whole team, the supporters and everybody at the club are really happy for him because he's a great team player," he added. "You get rewarded in this life when you work hard and we're delighted that he helped us win this game.
"Hopefully his confidence will be very high now, but I didn't mind when he wasn't scoring because as long as we win as a team that's all that matters to me."