The British number two was playing his first match since retiring during his third-round clash against Denis Shapovalov at the US Open with a back problem.
Edmund was particularly dominant on first serve in his 6-4 6-2 win against Australia's Tomic, winning 23 of 25 points and hitting nine aces.
Edmund loses to Donaldson in Chengdu
In the second round in China, sixth seed Edmund will face 20-year-old American Jared Donaldson.
Nadal beats Opelka in Rome semi-final
Djokovic to face Nadal in the final at the Italian Open for sixth time