Rob Mitchell’s team now face a quarter-final match against Huddersfield Town on February 6 after a magnificent 4-1 win against the current leaders of Northern Premier Division of the National League.
It looked like it was going to be one of those days when they trailed 1-0 to Sophie Domingo’s thumping 60th minute goal going into the final 10 minutes of the 90.
However Danielle Whitham stepped up to score an 81st minute free kick as the game went to extra time.
Brighouse, who needed 30 minutes of extra time to beat Newcastle United in the third round, suddenly found another gear and ended up running out 4-1 winners.
On 97 minutes Shauna Legge scored her first ever goal for the club with a stunning scissor kick to make it 2-1 and spark scenes of wild celebration.
Five minutes later Drew Green released substitute Imogen Williams, whose shot was parried by goalkeeper Sarah Morgan into the path of leading scorer Leah Embley, who made it 3-1.
As Derby County threw everything at Brighouse Williams added a fourth in the final minutes after more good work by Green to seal a memorable win.
The win hadn’t looked very likely as Derby County dominated the first half without finding a breakthrough.
The Rams’ stand-in captain Ellie Gilliatt rattled the crossbar after seven minutes from 40 yards while Jade Formaston had her header cleared off the line by the impressive Becky Gompertz midway through the first half.
When they did find a way through the visitors’ defence they were thwarted by goalkeeper Imogen Maguire, who was kept busy throughout.
Brighouse were much more attacking in the second half and it was against the run of play that Derby opened the scoring when Domingo latched on to a long ball to fire home.
The home side’s squad has been hit by Covid and they played into their opponents’ hands by trying to protect their 1-0 lead.
Mitchell brought on all his substitutes and former Derby player Monique Watson was sensational with her trickery and nearly grabbed a goal of her own but was denied by Morgan’s fingertips.
Blackburn Rovers’ loanee Isobel Dean came on for her debut as extra time ended with both goalkeepers making a series of saves to keep the score at 4-1.
After the game Mitchell was full of praise for his team. “When you’re playing against a top team like Derby County the key is to stay in the game for as long as possible,” he said.
“As soon as Danielle equalised late on I knew we had experience of winning in extra time and we were absolutely stunning.
“Imogen Williams and Monique Watson were excellent and Shauna Legge popped up with goal from a scissor kick. I’m proud of each and every one of them.”