Del Potro cruises through in Estoril
Defending champion Juan Martin Del Potro crushed Rui Machado 6-1 6-0 in the second round of ATP Estoril.
The Argentine world number 10 made light work of the unseeded Portuguese to set up a quarter-final clash with Spain’s Albert Montanes.
Del Potro hit four aces and won 70 per cent of his service points in just over an hour to move on to a 24-6 record for 2012.
"I like to play on clay, I prefer hard courts obviously, but I have been working hard at home, before I came here," Del Potro said.
"This tournament is very important to my clay-court season and for my confidence ahead of the Masters 1000 tournaments and Roland Garros.
"Albert is a two-times former champion here and a very good clay-courter so it will be a tough match. I am looking forward to it."
Del Potro, a one-time top-five regular, slipped down the rankings after a series of injuries but has battled back into the top 10.
His quarter-final opponent Montanes, seeded seventh, dropped the first set against American Bobby Reynolds but won 4-6 6-4 6-3 in a two-hour epic.
Joao Sousa is also through to the quarter-finals after fifth seed Denis Istomin retired from their match in the deciding set with the score at 3-6 6-3 4-2.
Home competitor Sousa will now face fourth seed Albert Ramos for a place in the last four after the Spaniard comfortably beat Germany's Bjoern Phau 7-5 6-0.