Antonio Conte has set Chelsea a 21-point target to be sure of clinching the Premier League title.
After a 3-1 win over Swansea City last month, Conte said he thought 29 points were required in order for the Blues to guarantee the return of the top-flight trophy to Stamford Bridge.
A hard-fought 2-1 victory against Stoke City on Saturday, secured by Gary Cahill's 87th-minute strike, sent Chelsea 13 points clear at the summit.
"This win is important, honestly. We played two games away, West Ham and Stoke, and to win both games is very important in this part of the season," said Conte.
"There are 10 games to go. I like to think that now we need to take 21 points to be sure to win the league.
"But today it is important against a strong team and in a stadium with a great atmosphere."
Conte confirmed that Eden Hazard was left out of the matchday 18 after sustaining a calf injury during a training session.
"In the last training he felt a bit of a problem in his calf, for this reason I decided not to risk him. That is why he didn't play," the Italian said.
With 20 minutes remaining Conte replaced Victor Moses with Cesc Fabregas, switching formation from 3-4-3 to 4-2-3-1.
The Chelsea boss knew his side risked conceding as a result, but wanted to actively search out an important win in the title race.
He said: "This is not the first time [the system was changed mid-game]. This happened against Burnley.
"When you want to take more risks, to try to take three points and not only one, to try to change. For sure there is the great possibility to score the goal, but also to concede a goal.
"You must know this, but then I prefer to decide and risk to take three points. In other situations, I decide to keep the result."