Champion Roger Federer [Images] completed an elegant half century on Thursday to reach the third round of Wimbledon.

The world number one's bid to emulate Bjorn Borg's five successive titles at the All England [Images] Club gathered momentum when he won his 50th consecutive grasscourt match 6-2, 7-5, 6-1 against Argentine teenager Juan Martin Del Potro.

While Federer's progress was never in doubt, Marat Safin [Images] set up an intriguing showdown with the Swiss by reaching the third round of the grasscourt Grand Slam for only the third time.

In the process he ruined Aisam-ul-Haq Qureshi's bid to become the first Pakistani to reach the third round here with a 6-4, 6-2, 7-6 victory.

Federer had been left hanging 2-0 up in the third set on Wednesday when rain suspended play. Although Del Potro is an exception among Argentines in preferring fast courts to clay, at 18 he simply did not have the experience or the tools to throw Federer off course.

The Swiss needed only 10 minutes on Thursday to complete formalities after Del Potro drove a forehand long.

Safin had been scheduled to play on Court One on Wednesday but did himself no favours with the organisers when he lashed out at what he saw as exorbitant prices in the players' restaurant.

On Thursday, officials demoted him to Court 18 and in a rather muted performance, the often volatile Russian produced an array of lobs and passing shots to outwit Qureshi, the first Pakistani to play in the main draw for 31 years. 

However, Safin's performance would hardly have instilled any fear into a champion who has won seven of their nine duels and has dropped just one set in his last 13 Wimbledon matches.

Three-times former winner Venus Williams geared up for a potential fourth round showdown with 2004 champion Maria Sharapova [Images] with a 6-2, 6-2 thrashing of 170th ranked Czech Hana Sromova.

Just 24 hours after creating a stir at the championships by emerging on court wearing red underwear, Tatiana Golovin [Images] discovered that red was not really her lucky colour.

"I'll keep wearing them as long as I keep winning, they are lucky," the 17th-seeded Frenchwoman had said.

She had obviously spoken too soon as on Thursday she became the highest women's seed to exit following a 6-2, 3-6 6-1 defeat by Austrian Tamira Paszek.

Serbian sensation and French Open runner-up Ana Ivanovic, seeded six, looked comfortable on grass to beat American Meilen Tu 6-4, 6-3.

Tommy Robredo became the first big casualty in the men's draw. The 11th-seeded Spaniard failed to last the distance against 36-year-old Australian Wayne Arthurs and fell 6-3, 7-7, 6-3.

• Wimbledon Championships 2007
• Complete tennis coverage
• All you want to know about Sania Mirza