Switzerland's Roger Federer reacts after beating Germany's Jan-Lennard Struff in their men's singles second round match on day four of the Australian Open tennis tournament in Melbourne on January 18, 2018. Pic/AFP

Defending champion Roger Federer advanced to the third round for the 19th straight Australian Open with an easy win over Germany's Jan-Lennard Struff on Thursday. The Swiss second seed was too strong for the 55th-ranked Struff, reeling off a 6-4, 6-4, 7-6 (7/4) victory in 1hr 55min in the night match on Rod Laver Arena.