Romelu Lukaku said Chelsea are "the hunters" of Manchester City in the title race after coming off the bench to score his first Premier League goal since September to help beat Aston Villa 3-1.
Reece James' own goal put Villa ahead, but Jorginho quickly levelled from the penalty spot in a clash between two of the many English sides hit by cases of coronavirus.
Lukaku was one of Chelsea's absentees due to a positive test for draws against Everton and Wolves last week that saw them lose ground in the title race.
But he made his return as a second half substitute and made an almost instant impact to head home Callum Hudson Odoi's cross.
The Belgian's blistering run then won a second Chelsea penalty in stoppage time that Jorginho slotted home.
"I needed a performance like this today," said Lukaku.
"We are the hunters now. The last results were not the best and now we have to chase. We have to treat every game like a final. Today we won and now we have to push on."
Thomas Tuchel's men move level on points with Liverpool, who have a game in hand, and back to within six of Manchester City, who were 6-3 winners over Leicester earlier on Boxing Day.
But Tuchel reiterated his criticism of being forced to play through a hectic festive period with the extra complication of Covid and without the use of five substitutions.
"They make us play all the time even if we have Covid. We have new injuries and it won’t stop," said Tuchel. "People in offices make these decisions."
Villa's own Covid outbreak saw manager Steven Gerrard forced into isolation after he tested positive on Christmas Day.
The home side got off to the perfect start when James flicked Matt Targett's effort over his own goalkeeper Edouard Mendy to open the scoring on 28 minutes.
However, the lead lasted just six minutes due to Matty Cash's rash challenge on Hudson-Odoi inside the area.
Jorginho was Chelsea's top league scorer last season despite all of his goals coming from penalties and the Italian international is his side's leading marksmen in all competitions thanks to nine spot-kicks this season.
- 'Super concerned' -
Lukaku will expect that to change over the coming weeks as the club's record signing finds his form after a disrupted start to his second spell at Stamford Bridge.
He is yet to start in the Premier League since suffering an ankle injury in October, with his positive test for Covid coming just as he was returning to full fitness.
"It’s not fair," added Tuchel. "He had a very good performance but he’s not ready for that even if he wants it.
"We’ve all been in bed for 10 days with flu. He was a game changer today. I’m super impressed with the guys but I’m super concerned."
A Lukaku in form is what Chelsea need if they are to mount a serious title challenge with clashes against Liverpool and City to come in January.
The former Manchester United striker took just 11 minutes to make the difference as he timed his run perfectly to meet Hudson-Odoi's cross and powered a header low past Emiliano Martinez.
Lukaku then powered his way through the Villa defence late only to be hauled down by Ezri Konsa.
Jorginho got the better on Martinez once more from the spot to seal a vital return to winning ways for the Blues.