Jose Mourinho’s side had swept to the top of the table with 10 wins from their 12 matches and only Manchester City and Manchester United had avoided defeat against the Blues in domestic action.
But Chelsea were unable to break down dogged Sunderland, who held the Blues without a goal for the first time in 20 matches in all competitions this season.
The west Londoners are now seven points clear of second placed Southampton, who host champions City on Sunday.
Chelsea winger Willian almost opened the scoring with a fiercely struck low shot that rebounded off a post.
Yet Sunderland were making it tough for Mourinho’s men and Santiago Vergini fired against the crossbar from 10 yards.
A tetchy encounter got even more heated when Chelsea striker Diego Costa escaped with a booking rather than a red card for an elbow on Sunderland defender Wes Brown.
“It was a difficult match. Only one team tried to win from the beginning, the other team didn’t. They defended a lot and they defended well,” said Mourinho, whose side remain unbeaten this season.
“We were a bit tired towards the end and we left a bit of space. But I’ve got nothing negative to say about my team.”