The Blues looked on course for the victory which would have taken them six points clear of their London rivals, and with a vastly superior goal difference, until Gylfi Sigurdsson's equaliser 10 minutes from time.
Oscar and Ramires had twice put Chelsea in front either side of Emmanuel Adebayor's stunning strike for Spurs, with interim boss Benitez bemoaning his side's inability to make the most of several good opportunities after the interval.
The Spaniard told Sky Sports: "We had four or five counter-attacks where we could finish the game. We didn't do it. We had the chances to score the third goal and finish.
"We could have defended better for both goals. We are talking about transition defending when we conceded the first goal and the second goal was the same - I think Adebayor's position was offside.
"We have to stay more compact and be more aggressive in defence.
"In the first half we had control of the game, the second half was too open. When we were winning the game I think we had to have more control.
"We have to win one game to guarantee the top four. We will try to win both to be in the top three.
"With our counter-attacks we have to do something more. We had the chances to score the third goal and finish the game but we didn't do it. Credit to Tottenham, they were pushing and they were attacking."