JOIN USSafin bids adieu with defeat
The 29-year-old Russian, who had saved three match points to squeeze past French qualifier Thierry Ascione in the first round of his final tournament on Monday, fought bravely against the Argentine world number five. Showing glimpses of his old form, Safin, who has not won a title since the 2005 Australian Open, challenged Del Porto by winning a tight second set.
Safin, who held the number one spot for several weeks in 2000 and 2001 but has dropped out of the top 50, was broken in the third game of the decisive set and his opponent then stayed in control.
The Russian, who won the Paris event three times, saved a match point at 5-3 down with a forehand winner but Del Potro then served for the match, sealing victory with an ace.
Novak Djokovic survived a fightback by Argentine Juan Monaco to win 6-3, 7-5 and reach the third round of the the Paris Masters on Wednesday.
Swede Robin Soderling, seeded ninth, kept alive his slim hopes of making the Nov. 22-29 World Tour Finals in London by beating towering Croatian Ivo Karlovic 6-4, 7-6 to set up a third-round match against Russia's Nikolay Davydenko.
Earlier on Tuesday, Russia's Nikolay Davydenko and Spain's Fernando Verdasco moved closer to spots at the World Tour Finals with contrasting second-round wins.
World number seven Davydenko, who will enter the season finale with a semifinal appearance here, brushed aside German Benjamin Becker 6-2, 6-1. Verdasco, the world number eight, who will a book a trip to London if he wins the title but could qualify earlier depending on how other contenders fare, needed over two hours to move past Italian Andreas Seppi 6-7, 6-4, 6-4.
The Spaniard's win meant Czech Radek Stepanek and Croatia's Marin Cilic dropped out of the race, leaving just five players fighting for the two remaining tickets to the London event featuring the world's top eight players, with Davydenko and Verdasco first in line.
The other three are Swede Robin Soderling, Chilean Fernando Gonzalez and France's Jo-Wilfried Tsonga, the defending champion in Paris.
World number nine Tsonga, outclassed Spaniard Albert Montanes 6-1, 7-5 in a second-round match.