France's [Images] Sebastien Grosjean advanced to the fourth round of the Australian Open after he upset sixth seed Guillermo Coria 6-2, 6-2, 3-6, 6-4 on Saturday.

Spain's Tommy Robredo and seventh seed Ivan Ljubicic also advanced to the fourth round with straight-sets wins over their respective opponents on Friday night.

Robredo, seeded 16th, had not beaten Blake in four previous meetings, including a Davis Cup rubber that was not completed, but chose his moment perfectly, winning 6-3, 6-4, 6-4 in less than two hours while Ljubicic extended his good start to the new year with a 7-5, 7-6, 6-0 victory over Spain's Feliciano Lopez .

Grosjean, a former semi-finalist at Melbourne Park, had two opportunities to serve for the match in the fourth set but was broken by the stubborn Coria while leading 5-2 before he sealed victory at the second attempt.

Coria had severe problems with his serve making 23 double faults. He also received medical treatment for a cut finger on his left hand.

The 25th-seeded Grosjean now faces compatriot Paul-Henri Mathieu in the fourth round after the Mathieu beat Peru's Luis Horna 7-6 7-6 6-1.

Blake had gone into the match as favourite despite being seeded four places behind Robredo following his victory at last week's Sydney International but gave himself no chance by committing 46 unforced errors compared to the Spaniard's 14.

Robredo's win puts him into the fourth round at Melbourne Park for the first time in six attempts. He will play Argentine fourth seed David Nalbandian on Sunday for a place in the quarter-finals.

Ljubicic, who beat Carlos Moya [Images] in the Chennai Open final before arriving in Australia, is unbeaten in seven competitive matches in 2006 and this victory moved him into the fourth round at Melbourne Park for the first time in seven appearances.

The 26-year-old, in Croatia's Davis Cup-winning team in December, dominated against the left-handed 31st seed despite the close score in the first two sets.

The match would have been closer to a rout had Ljubicic converted more than just five of the 17 break points he accumulated. Three of his five breaks came in the final set.

Ljubicic will now meet 2002 Australian Open champion Thomas Johansson in what should be a raucous occasion.

Johannson, who beat Gilles Simon of France 6-3, 6-2, 6-1 in the third round, has been cheered by a large group of Swedish fans wearing traditional blue and yellow t-shirts and Viking helmets while Ljubicic has been well-supported by Melbourne's expatriate Croatian community.

• Complete tennis coverage
• All you want to know about Sania Mirza