Grigor Dimitrov capitalized on Stan Wawrinka's awful display Thursday to rout the defending champion 6-1, 6-2 and reach the quarterfinals at the Monte Carlo Masters.

Wawrinka got off a sluggish start and never found the right balance. He also failed to seize his chances, failing to convert four break points in the sixth game of the second set.

The seventh-seeded Swiss player was hoping to advance deeper at the clay-court Masters tournament following a series of disappointing results on hard court.

But he could not follow up his solid opening-round showing, hitting 13 unforced errors as Dimitrov raced to a 4-0 lead. The Bulgarian player fended off Wawrinka's assault in the sixth game and broke for 3-1 in the second set after the former Australian Open champions shanked three forehands.