Di Matteo: Chelsea need to win eight in a row
Victory on Saturday would have moved them within two points of fourth-placed Tottenham but the closest the hosts came in a disappointuing derby was Juan Mata's second-half free-kick which struck the inside of the post.
Third-placed Arsenal's 3-0 victory over Aston Villa meant the Gunners charged eight points clear of Chelsea, meaning a scrap with Tottenham for fourth spot and a berth in the qualifying round for next season's Champions League.
Chelsea have qualified for every Champions League competition since Russian billionaire Roman Abramovich bought the club in 2003.
"We were looking to win the game and close the gap [but] we have to give credit to Spurs, they defended well and played a good game," Di Matteo told the club's website.
"From the day I was appointed we all knew it would be a difficult task but there are still eight games to go and we will try to win as many as we can to try and gain fourth spot. To make the gap up we will have to win all of our games."
Apart from Mata's free-kick, Daniel Sturridge's shot across the face of goal and a penalty appeal when Tottenham's Benoit Assou-Ekotto appeared to make contact with Ramires in the area, Chelsea failed to apply any sustained pressure.
Tottenham also hit the woodwork in the second half through Gareth Bale's header while Emmanuel Adebayor should have scored when he was played in by Luka Modric's lob but his weak shot was cleared off the line by Gary Cahill.
Petr Cech also made a fine save from Bale's stoppage-time free-kick as Spurs pressed for their first win at Stamford Bridge since 1990.
"It was an important point," said Tottenham manager Harry Redknapp. "The longer it went on, we were getting at them and I could see us winning it.
"They were probably happier to hear the final whistle than we were. We kept getting corners and free-kicks in dangerous positions but I thought Cech made a couple of great saves.
"The one from Bale low down was a fantastic save where the ball pitched right in front of him. He did really well to get a hand to it," added Redknapp.