Second half goals from Chelsea Cornet and Kirsty Howat booked the Light Blues a return to Hampden next month to face Spartans or Hearts.
The Gers gaffer believes her side thoroughly deserved the victory and hailed Cornet for timing her run to head home Rachel Rowe’s corner for the crucial opener perfectly.
Speaking to Rangers TV, she said: “I think it was deserved and I don’t think anyone can doubt that.
“We dominated from minute one and there was never a moment where I was worried or panicked about not winning the game.
“I was just waiting for someone to take their chance and I think it was a good day all round.
“You have to earn that right, we got our structure and shape spot on. Tactically, the girls delivered what I asked them to, to limit opportunities.
“We knew we could create chances and it was important we got our out of possession work right and it was spot on.
“That allowed us to create in possession because I knew we would make chances and keep the ball for long periods of time.
“Out of possession won us the game and helped us score two good goals.
“We saw the importance of set-pieces. We spoke about that at half-time, they were looking for a set-piece moment and to get free-kicks and corners and they are dangerous from them.
“But we know we have good delivery and timings, when they are zonal you can get across bodies. Chelsea did that and she has great timing and the ball finds her nine times out of ten.
“She scored the other week and she replicated it at a big moment.”
Rangers suffered a 2-1 defeat to their rivals last month in the league campaign.
Potter believes her squad have learned lessons from that game and despite looking forward to a return to the national stadium next month, she insists the visit of Hearts on Wednesday is her top priority.
She added: “In certain positions you have to dominate.
“The last game against them, that didn’t happen and that showed me we have learned from it and put right the wrongs.
“We knew if we did that it would put us in a good position to win the game, so it was important to do that as it allowed us to win and get into another final.
“We have a few big games coming up starting with Hearts on Wednesday which we won’t overlook.
“We are back in this week to do our work right.
“This is a big one ticked off for us but we can’t afford another slip up and we have to concentrate on one game at a time.”