Trabzonspor striker Marc Janko opened the scoring for the hosts after 14 minutes, capitalising on Zlatko Junuzovic's flick, while Marko Arnautovic should have added a second a few minutes later but was denied by the post.
Luis Suarez then cannoned a free-kick off the crossbar just before the break as Uruguay responded, before Pereira pounced on a goalmouth scramble to equalise midway through the second half.
Austria coach Marcel Koller named a strong side, eager to begin his side's preparations for their UEFA Euro 2016 qualifying campaign early.
Despite missing Paris Saint-Germain's Edinson Cavani with a thigh injury, Uruguay still named a talented starting line-up, with record cap holder Diego Forlan making his 108th international appearance.
They nearly doubled their lead five minutes later, as David Alaba's free-kick forced Muslera into a stunning save, before Arnautovic lashed the rebound off the post and wide.
The Liverpool striker was in the thick of things once again 15 minutes before the break, flicking Cristian Rodriguez's set-piece into the path of Jose Maria Giminez, who looped his effort over the crossbar from point-blank range.
Austria continued to attack themselves, though, and they nearly had an unlikely second just before the break when Alaba's audacious lob forced another brilliant save from Muslera.
And parity was finally restored five minutes later when the hosts failed to deal with teasing free-kick from the left and Gimenez's flick found substitute Pereira, who tapped home.
