Kerr, who injured her calf during the Women's World Cup this summer, said on Wednesday she was "only on the way back up now" as she deals with the "process" of returning to full match fitness.

But there was no sign of rustiness from Kerr on Thursday as she sealed her hat-trick with an audacious lob from outside the box, before heading off to a standing ovation midway through the second half.

"Well, if that's her at 80% - or whatever she is - I'll take that every week," said manager Emma Hayes afterwards.

"That's not bad. I can't wait for the 100% version!"

Kerr has been a prolific goalscorer everywhere she has played and continues to deliver for Chelsea on the big stage. Hat-tricks come so frequently that she was even happy to give away the match ball to a young fan in the stands.

Those at Stamford Bridge hoped she would produce her trademark backflip after the third goal but she instead slid on her knees towards supporters and grabbed the Chelsea badge on her shirt afterwards.

"I felt like I was lucky with my first touch for my hat-trick goal but then I saw [the goalkeeper] back-pedalling so I thought I'd try the lob. I don't mind those ones to be honest!" Kerr told Dazn.

"I am getting really close to 100%. I just need more consistency, more training and more games. This last block [of fixtures] has been difficult because you don't train that often. I am pretty close but I'm not quite there yet."

'Combination of Kerr and Kirby is frightening'

Emma Hayes was frustrated by Chelsea's first-half performance but said the substitutes made a difference

Kerr's threat is so great that Paris manager Sandrine Soubeyrand was asked if she had considered a special plan to deal with her specifically.

"It's not my style usually to make plans for individuals. If you make plans for one player [at Chelsea], you will be making a lot of plans because there's a lot of quality players," she said.

"Kerr was excellent tonight. I think she had four shots and converted three of them."

The Chelsea striker is the first player in this season's group stage to score three or more goals - although her hat-trick did not come as a surprise to her manager.

"I fancied her to score a hat-trick tonight. I said it in the dressing room beforehand," said Hayes.

"By her standards, she's not top, top level yet but I don't know anyone who puts the ball in the net like she does. She's so alert and so decisive with her moments. The third goal she lobbed was brilliant centre-forward play."

Kerr's two second-half goals were also influenced by England midfielder Fran Kirby, who came on a substitute and is also bidding to return to full fitness after missing most of 2023 with a knee injury.

Former Chelsea defender Gilly Flaherty told BBC Radio 5 Live Kerr was "clinical" and also applauded Kirby's impact.

"Kirby changed the game when she came on, especially with the link-up [she had] with Sam Kerr. They looked like a different team in the second half," said Flaherty.

Northern Ireland boss Tanya Oxtoby added: "The combination of Sam Kerr and Fran Kirby... to be able to call on such a pairing is a frightening prospect for any opposition.

"Chelsea just have more quality and have been more clinical than Paris FC."

Kirby was forced to miss the World Cup and Hayes said there had been ongoing conversations with England manager Sarina Wiegman on how to manage her minutes.

"I rated Paris FC and I felt there was a lot of work to do out of possession which, over a 90-minute period, I felt would be too much for Fran [Kirby]," added Hayes.

"I said to Sarina this morning 'it's so important we keep her healthy for England and Chelsea'. She wants to play at every moment but I felt that was the perfect cameo for her.

"The team needed it. I felt we weren't close enough to Sam [Kerr] in the first half. We were sloppy and I think the accumulation of games caught up with us. I don't think people realise how hard it is to keep doing it.

"It was a performance in which we dug something out. But the strength came from the bench tonight."