Paris: David Nalbandian enhanced his reputation as Roger Federer’s nightmare opponent by upsetting the world number one again with a 6-4, 7-6 win in the Paris Masters Series third round on Thursday.

Eleven days after beating Federer in the Madrid Masters final, the unseeded Argentine showed more composure when it mattered to oust the elegant Swiss, who had already made sure of ending the season in top spot for a fourth consecutive year.

Nalbandian, now tied at 8-8 with an opponent he famously defeated in the 2005 Masters Cup final, goes on to meet Spain’s David Ferrer for a place in the semi-finals.

Ferrer, seeded fifth in the $2.45 million indoor event, advanced to the last eight by knocking out Czech Tomas Berdych, the 2005 Paris champion, 6-4, 6-2.

British No. 1 Andy Murray had earlier moved closer to a Masters Cup spot by crushing Frenchman Fabrice Santoro 6-4, The Scot faces Frenchman Richard Gasquet, who had a 6-4, 6-4 win over American James Blake.

World number two Rafael Nadal advanced in determined fashion with a 6-4, 6-3 win over Swiss Stanislas Wawrinka.

The Spaniard next meets Russia’s Mikhail Youzhny, who ended German Tommy Haas’s Masters Cup hopes by beating the German 6-4, 1-6, 6-3.

Nikolay Davydenko, meanwhile, was again accused of not trying his hardest in a tennis match, with the chair umpire criticising the Russian’s serving during a 2-6, 2-6 loss to Marcos Baghdatis in the third round.

The defending champion, who was booed, finished with 10 double-faults and 36 unforced errors. He lost serve five times.

Chair umpire Cedric Mourier spoke to Davydenko during a changeover, asking him what was wrong with his serve. Davydenko responded by asking what else he could do. “Serve like me,” Mourier said. “If you serve like me, you put it in the box. That’s it.” (Reuters)