Ethier finished off the big 10th frame with a two-RBI base hit after home runs by Mark Ellis and Yasiel Puig had accounted for three runs.
The Dodgers captured their sixth in a row and have posted a 23-5 record since June 21. Toronto's losing streak reached seven games.
Toronto overcame an early 2-0 deficit on a two-run double by Brett Lawrie in the fifth and the Blue Jays took the lead in the eighth with a run that scored on a throwing error by first baseman Adrian Gonzalez.
The Blue Jays' Casey Janssen, however, could not protect the lead in the ninth. He walked Puig to lead off the inning, then struck out the next two batters only to give up a base hit to Ethier that allowed Puig to score all the way from first base.
The five runs in the 10th all came off Juan Perez (1-2). Juan Uribe drew a one-out walk and scored on the homer by Ellis. Puig then delivered a solo shot, after which Gonzalez walked and Hanley Ramirez doubled Gonzalez to third.
Both runners scored on Ethier's double to left center.
The win went to Brandon League (5-3), who worked the bottom of the ninth after the Dodgers had tied the game.