Rafael Nadal said he felt sorry for Juan Monaco after he won 17 games in succession to coast into the French Open quarter-finals on Monday with a 6-2, 6-0, 6-0 demolition of the Argentine.
The defending champion, bidding to become the first man to capture seven Roland Garros singles titles, will tackle fellow Spaniard Nicolas Almagro for a place in the semi-finals.
"He was unlucky in the first set and the score of 6-2 was too much. I felt sorry for him, he was suffering on court," said second seed Nadal.
"I was sad for him. It's tough to accept that you are losing 6-0, 6-0."
Nadal, who celebrated his 26th birthday on Sunday while title rivals Novak Djokovic and Roger Federer were struggling into the last eight, took his career record in Paris to 49-1.
Monaco, the 13th seed, went into Monday's match with solid claycourt form under his belt having captured titles in Vina del Mar and Houston this year.
But he had lost all three previous clay meetings against Nadal, claiming just 10 games in the process, and the 28-year-old was swept aside again by the champion in just one hour and 46 minutes on Suzanne Lenglen court.
Nadal will start his quarter-final as comfortable favourite as he leads Almagro 7-0 in their series.