Bolt, looking to retain his other individual sprint title after that extraordinary 100m victory here in the Bird's Nest, looked to be saving his strength for the next showdown as he eased off in 19.95 seconds.
Gatlin, comfortably the fastest man in the world this year over 200m, as he was over 100m, ran a controlled 19.87 as he seeks revenge for his shock defeat on Sunday night.
