After grinding out a win when the first set went to a tie breaker, Jabeur kept Gauff under pressure, breaking Gauff three times in the second set before converting her second match point.
“I’m very confident on this surface, so I just tried to play my shots, she (Gauff) plays with a lot of power so coming into the match, I knew I had to play my own game,” said Jabeur.
The Tunisian, ranked fourth in the world, became top seed in Berlin after both world number one Iga Swiatek pulled out to rest a shoulder injury ahead of Wimbledon.
“It means a lot to be in the (Berlin) final,” said Jabeur.
“I had no great expectations, I came here as fourth or fifth seed and then ended up first, but grass suits me well.”
Earlier in the day, Bencic came from behind in her semi-final against Maria Sakkari, a match which lasted over three hours in scorching temperatures.
Bencic rallied from losing the hard-fought first set, which lasted 76 minutes, to secure a 6-7 (6/8), 6-4, 6-4 win in temperatures of around 33 degrees Celsius (91 degrees Fahrenheit) in the shade.
