Opening the batting alongside Chris Rogers — Australia's confirmed top two for the first test against England starting July 10 — Watson struck 14 fours and two sixes to bring up three figures at New Road before lunch on the first day of the four-day game. He eventually departed for 109.
The quick-scoring Watson made 90 off 94 balls in last week's tour match against Somerset, which Australia won to boost confidence ahead of the Ashes.
Rogers, who is line to make his first test start in more than five years next week at Trent Bridge, made a more circumspect 75 to show he is also in good nick ahead of the series against England.