The former Everton star and Australian international netted a brace as New York Red Bull made it two road wins in a row, and three from their past four, with a 2-1 triumph over Toronto FC at BMO Field.
Cahill fired the Red Bulls ahead in the 39th minute with a side-footed finish with his left from a Roy Miller pass before producing an 89th-minute winner with a back post header from Thierry Henry's chipped ball.
The goals were Cahill's first of the 2013 MLS campaign and allow him to become the first New York player to win the weekly award this season.
2013 MLS Player of the Week
Week 9: Tim Cahill (New York Red Bulls) Week 8: Jack McInerney (Philadelphia Union) Week 7: Brad Davis (Houston Dynamo) Week 6: Ryan Johnson (Portland Timbers) Week 5: Will Johnson (Portland Timbers) Week 4: Juan Agudelo (Chivas USA) Week 3: Bill Hamid (D.C. United) Week 2: Robert Earnshaw (Toronto FC) Week 1: Mike Magee (LA Galaxy)