Youkilis got his RBI with a single, double and sacrifice fly in Boston's sixth win in seven games.
Rocco Baldelli hit a solo home run and Alex Gonzalez singled in a run for the Red Sox.
Winning pitcher Paul Byrd (1-0), making his first appearance since September of 2008, scattered three hits in six scoreless innings.
Roy Halladay (13-8) was the loser, giving up four runs and seven hits in six innings.
The Blue Jays have lost five of six.
Copyright 2009 by United Press International.