Conor Gallagher apologised to fans of his former club Crystal Palace after scoring twice, including a crucial stoppage-time goal, to help Chelsea to a come-from-behind 3-1 win in the Premier League.
The victory on Monday (Tuesday AEDT) has ignited Chelsea's hopes of a finish in the European positions.
Two season ago England midfielder Gallagher spent a year on loan at Palace, where he scored eight goals and excelled in making late runs into the area.
Now he's doing that for Chelsea, steering home an equaliser at Selhurst Park barely 90 seconds into the second half, then putting his team ahead just after 90 minutes had been played with a strike from the edge of the box.
"I do love them," Gallagher said when asked how he felt to have inflicted pain on the Palace supporters.
"It's sad, but you can't beat that feeling. Sorry, Palace fans."
Argentina international Enzo Fernandez secured the points in the fourth minute of added time to leave Palace just five points above the relegation zone and their 76-year-old manager, Roy Hodgson, under more pressure.
Chelsea climbed to 10th place in what remains another disappointing campaign for a club that have spent more than $US1 billion on players over the past two years.
However, they could still end in qualification for the minor European competitions, with seventh-placed Newcastle only two points away.
"We are trying our best to keep improving," Gallagher said.
"Consistency is the biggest thing for us - there have been games when we've been brilliant and games when we've been terrible."
The 24-year-old Gallagher isn't one of Chelsea's many costly recent arrivals - he is a product of the club's youth academy - but is proving to be one of the best-performing players under Mauricio Pochettino, whose own position has come under scrutiny this season.
A thumping long-range strike by Jefferson Lerma gave Palace the lead in the 30th minute of a first half when Chelsea was lacklustre, failing to register a single shot on target.
"It was extremely cruel, but the game is about goals and unfortunately we made mistakes which led to goals," Hodgson said.
"I don't think that is a fair reflection on the way the game was played. I think we deserved to come off with at least one point."
It was a 13th straight win for Chelsea over Palace.
Australian Associated Press