The 19-year-old South African, only cleared to compete again in July after controversial gender tests had put her career on hold since winning the world title in August 2009, ran one minute 58.16 seconds to win easily.
Just 10 days ago a dejected-looking Semenya had finished ninth in a time of 2:07.16 at a meeting in Rovereto in Italy.
The Commonwealth Games take place in New Dehli between Oct 3-14.
Semenya clinched World Championship gold at the Berlin meet last year.
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