Mixing his trademark power groundstrokes with dropshots and deft touches at the net, the 22-year-old number eight seed broke his opponent once in each set in a first-round match that was twice interrupted by rain.
Mayer, 32, beat the Austrian in their last grasscourt encounter -- the semi-finals of the Halle tournament earlier this month, which the German went on to win. Thiem wrapped things up on his first match point when Mayer hit a service return long, the Austrian having benefited earlier in the game from a service ace that Hawkeye showed had just clipped the centre line.