Wang (2-2), making his third start of the season, managed to hold the Blue Jays to two runs over five innings despite his wildness. The right-hander allowed four and struck out five.
Bryce Harper went 3-for-4 with a solo homer while Danny Espinoza added a two-run shot and Jhonatan Solano cracked his first major-league round-tripper as the Nationals took the opener of a three-game series.
Toronto's Henderson Alvarez (3-6) was tagged with the loss, allowing four runs on nine hits over seven frames.
Jose Bautista socked his 18th homer for the Blue Jays.
Couple mistakenly served bag of cash at McDonald's drive-thru
Jordana Brewster on Paul Walker: 'He was an enormous presence in my life'