The winger stepped up to bury the crucial third goal from the spot in first half injury time as we recovered from going 1-0 down to lead 3-1 at the break.
Harry Kane and Danny Rose were also on target in the first half and Harry soon made it 4-1 in the second half. Chelsea responded via Eden Hazard's goal before Nacer Chadli made the game safe at 5-2.
Andros' penalty gave us that key two-goal lead and he didn't hesitate to take responsibility after Harry was upended by Gary Cahill.
"There were a few nerves," he admitted. "I knew that the goalkeeper would know which side I was going to go so it was all about making sure I put enough power on it to make sure it went past him and thankfully that was the case.
"The shot had too much power for him and went in. I just wanted to make sure I got enough power on my strike so that even if he read it the power would take it in.
"When we came in at half-time the main thing was just to focus – the first 10 to 15 minutes after the break we needed to stay compact and to go on and score a fourth was beyond our wildest dreams.
"We’re not happy with conceding three goals but at the end of the day this is a Chelsea team that was tipped to be the invincibles and we’ve got three points against them."
Below: Andros celebrates his penalty strike
Although Andros' goal was key, Harry did the business once again with an equaliser out of the blue - and Andros was quick to praise his fellow Academy graduate.
"When Chelsea go in front they normally control the game and go on to win quite comfortably but when you’ve got a player like Harry who’s been on fire all season he can score a goal from literally anywhere. It was a great goal to get us back in the game."