Having been pipped in a tight opening set by No.8 seeds Julia Goerges and Nenad Zimonjic, the tide began to turn in the third game of the second when a clever passing shot from Groenefeld secured an early break. A second soon followed before Groenefeld comfortably served it out to force the match tie-break.
They continued to pile on the pressure in the tie-break, an exquisite wide return from Rojer helping them to a 6-3 lead, closing the match out soon after when Goerges netted a backhand volley.
For Groenefeld, the 4-6, 6-2, 10-7 victory ended a five-year wait to add a second Grand Slam success to the Wimbledon crown she won alongside Mark Knowles.
"I think it's always different. It's now five years since my last one in Wimbledon, and it's just as exciting this time around," Groenefeld said. "So maybe it helped a little bit, but, I don't know.
"But at the end, you're still thinking, 'Oh, my God, it's match point.' I'm very happy how we finished the match. Before we went out on court we talked about that we wanted to play our game, be aggressive, and I think we were always very positive.
"There was never a letdown, even after we lost the first set. We just kept going, and it paid off in the end."
Groenefeld and Rojer, who also came from a set down to defeat No.3 seeds Yaroslava Shvedova and Bruno Soares in the semifinals, were playing together for the first time, a decision they only reached after a last-minute change of heart from the Dutchman.
"I knew she was a quality player, of course," Rojer said of the decision. "I was actually set with someone else. I had to tell that person no, because I wanted to give it a shot.
"I think we are going to be on the same team at Wimbledon, as well, so it was nice to have the opportunity to play now also. It was quite an easy decision for me at the end."