Chelsea missed their Covid-hit first-choice strikers as they suffered another setback in their Premier League title challenge when they were held to a 1-1 home draw by Everton on Thursday, leaving the Blues four points adrift of leaders Manchester City.
Chelsea failed to turn early dominance into goals before Mason Mount made the breakthrough in the 70th minute when he took a pass from Reece James and fired past Jordan Pickford.
Mount had missed one of the European champions' many chances in the opening period when, clean through, he was denied by Pickford's outstretched foot. But his goal when it came was his fourth in four league games for the Blues. He is Chelsea's youngest player ever to score in four consecutive games.
The visitors drew level within four minutes of Mount's strike when Anthony Gordon floated a looping free-kick to the far post and 19-year-old Jarrad Branthwaite stretched out a boot to turn the ball in for his first goal for Everton.
Chelsea, who drew with Manchester United and Burnley in recent home games and lost at West Ham United, struggled to make further inroads without Romelu Lukaku, Timo Werner and Callum Hudson-Odoi, who all tested positive for Covid-19.
Kai Havertz was also unwell and was awaiting the results of a test.
Chelsea coach Thomas Tuchel said the result was "hard to swallow" but added that he would not use the absences as an excuse for the failure to keep pace at the top of the table.
"I think we missed big chances in the first half to get things straight and in the second half we did not find the rhythm consistently," he told BT Sport. "We gave it away with one free kick."
Everton were even more patched up than Chelsea with Demarai Gray and Salomon Rondon joining a list of injuries including playmaker Richarlison and centre-forward Dominic Calvert-Lewin.
That gave opportunities to young players including 20-year-old striker Ellis Simms who made his debut at centre-forward.
Both teams included two goalkeepers among their substitutes in a sign of the devastation in their ranks.
"Great character shown, we are coming back in a lot of games. The way they worked we deserved something," Everton boss Rafael Benitez said. "We have had too much bad luck with injuries. The reaction of the team was fantastic."
The draw left Chelsea in third place on 37 points behind Manchester City on 41 and Liverpool with 40 points after they beat Newcastle United 3-1 at Anfield on Thursday.