"I really wanted to win that match, it didn't matter if I had to win one set, but I don't want to go out with losing the match and still being in the semi-finals. I think that's a bit weird," Goerges told reporters.
The 29-year-old German extended her winning streak to seven games, having lifted the Kremlin Cup in Moscow, which was her first title of the year.
Mladenovic, the world number 10, ended her season with a disappointing 12-match losing streak, dating back to Washington in early August.
Goerges dominated the early exchanges, producing an array of forehand winners to break the Frenchwoman twice and claim the opening set.
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The two players exchanged breaks of serve in the second set before Goerges overcame a tiebreak to wrap up the victory in an hour and 36 minutes.
Goerges awaits Latvian Anastasija Sevastova in the semi-final, while American CoCo Vandeweghe will face Australia's Ashleigh Barty, the youngest player in the tournament at 21.
Chinese wildcard Peng Shuai finished her season with a win after her opponent Russia's Elena Vesnina was forced to retire due to a back injury while trailing 6-2 1-0.
U.S. Open winner Sloane Stephens also retired injured from her match at 5-0 down in the first set to Barbora Strycova of Czech Republic.
(Reporting by Hardik Vyas in Bengaluru; Editing by Christian Radnedge)
