Chelsea had the opportunity to go six points clear of second-placed Manchester United, who lost 3-0 at Fulham on Saturday, against a struggling West Ham side scrapping for their lives near the foot of the table.
"One more point is four points ahead which is good because we didn't play a good match," the Italian told the club's website after the London derby.
Chelsea have suffered a dip in form this month, notching five points from a possible 12 although champions United have also been inconsistent, losing two of their last three games.
"For every team ... it is not the best period. There are a lot of games and if you play every three days it's not easy," said Ancelotti after Frank Lampard's thrice-taken penalty in the second half cancelled out Alessandro Diamanti's 45th-minute spot-kick.
Chelsea face a busy festive programme, visiting Birmingham City on December 26 before hosting west London rivals Fulham two days later. Title rivals United have fixtures on December 27 and 30.
West Ham manager and former Chelsea favourite Gianfranco Zola said the league leaders were capable of lifting the trophy in May.
"I don't think Chelsea is in the best moment but they are not the only ones. They have what it takes to win the title," said the Italian.
Former international striker Zola left Parma, when Ancelotti was in charge, for Chelsea in 1996.
England midfielder Lampard showed nerves of steel when he was twice asked by the referee to retake his penalty against his international colleague, West Ham keeper Robert Green, because of encroachment into the area by players from both teams.
"I know Greeny from England, we practice," said Lampard.
"It's a bit of mind games really, you keep wondering whether you should go to the same side (of the goal) again."
