At the end of 90 minutes, the score was locked at 1-1 to force extra time. And the Miners were by far the better side in the 30 minutes, scoring three unanswered goals to book a place in the final.
They become the first club to reach this season’s final and will face the winner of the second semi-final clash between Medeama and Hearts of Oak.
The Miners, tipped by many as favourites, went ahead before halftime through Eric Esso who curled a free kick over the wall and into the net.
Berekum Chelsea equalised six minutes into the second half as substitute Stephen Sarfo slotted home from close range.
It was the only goal scored in the second half with both teams failing to convert decent chances to win the encounter.
The game went into extra time, in which Ashgold proved too strong for Berekum Chelsea who had a man sent off.
The Miners scored three goals with the first coming from Amos Nkrumah who buried the ball into the net from 25 yards.
Few minutes after the goal, Benjamin Baidoo was sent off for a second bookable offence.
Ashgold wasted no time in increasing their lead courtesy of Amos Addai who was left unmarked in a very good position.
With the game certainly won, Seth Osei added his name to the scorers by making it 4-1.
While Ashgold were celebrating following the full-time whistle, Chelsea players looked dejected.
The Blues were hoping to reach their first final after causing a major upset in the quarterfinals as they eliminated Kotoko.