Raheem Sterling celebrates after scoring Chelsea's first goal on Tuesday.
CNN  — 

Since the ownership group led by American businessman Todd Boehly spent more than than $5 billion on buying Chelsea last year, they’ve seen very little return on their investment.

Over $600 million has been spent on new players, but the club finds itself floundering 10th in the Premier League and struggling for form.

There have subsequently been questions raised about manager Graham Potter’s future at the club, but the side’s 2-1 aggregate win against Borussia Dortmund in the Champions League on Tuesday could be the turning point that everyone at Chelsea needs.

Potter, who looked like the most relieved man at Stamford Bridge after his side overturned a 1-0 defeat from the first leg, was seen hugging a jubilant Boehly as the teams made their way back to the dressing rooms.

“I’m still here,” Potter joked with reporters when asked about the brief meeting.

Goals from Raheem Sterling and Kai Havertz secured the win that sends Chelsea through to the quarterfinals of Europe’s most prestigious club competition.

It also marks an upturn in form after Chelsea went through the whole month of February without a win. During the bleak period of results, Potter opened up about the mental toll its taken on him and his family.

“Inevitably in life, you are going to have bad times and you’re going to have good times. Things are never bad forever, thankfully. But it felt like that sometimes,” he added after Tuesday’s match.

The victory wasn’t without controversy though, with Chelsea’s second coming from a retaken penalty after Havertz saw his first attempt saved by Alexander Meyer.

The referee had spotted players encroaching into the box before the first effort, so the Chelsea striker was given a second chance to put his side ahead.

Graham Potter praised the "special" win at Stamford Bridge.

“I was a bit nervous,” he told reporters, talking about the penalty incident. “But I scored, and that’s the most important thing.

“I tried to wait, to look at the goalkeeper, and I saw that he was going to go to the same side again.”

Jude Bellingham angry

The decision to allow Chelsea to have another chance at the penalty angered Dortmund’s young midfielder Jude Bellingham who was disappointed the spot-kick was awarded in the first place after the ball struck defender Marius Wolf’s hand.

“I’m not sure what more he can do with his hand,” Bellingham told BT Sport, referring to Wolf. “That in itself was disappointing and the fact that they’ve had a retake, I think it’s a joke.

“For every penalty, especially when you have such a slow run up, there’s going to be people encroaching into the box by a yard or so. He has made the decision and we have to live with it.”

Bellingham, who has been outspoken about refereeing decisions in the past, was trying to be careful with what he said.

“I’ve paid enough to them lot,” he added, referring to fines he’s received for post-match comments in the past.

Chelsea fans celebrated the full-time whistle with huge celebrations and will hope their side can now kick on and improve on its lowly position in the league table.

Potter’s side faces a trip to Leicester in its next match on Saturday before hosting Everton the week after.