Lisbon: Former U.S. Open champion Juan Martin del Potro staged a remarkable second-set comeback to beat top-seeded Swede Robin Soderling 6-4 7-5 and reach the last four of the Estoril Open on Friday.
Argentine Del Potro, a former world number four currently ranked 46th after missing most of last year with a wrist injury, broke Soderling`s serve in the fifth game to claim the first set.
World number five Soderling battled back, however, and raced to a 4-1 lead in the second set before heavy rain and a hailstorm forced the players to run for the locker-room.
Eighth seed Del Potro, who beat Roger Federer to win the U.S Open in 2009, made an immediate impact when play resumed over two hours later, winning six out of seven games to turn the second set around.
The tall Argentine will meet Pablo Cuevas in Saturday`s semi-final after the Uruguayan, ranked 61st in the world, beat sixth-seeded Brazilian Thomaz Bellucci 6-4 6-2.
The other quarter-finals were delayed until Saturday due to the rain, with South Africa`s Kevin Anderson to play second-seeded Spaniard Fernando Verdasco and Frenchman Gilles Simon meeting Canada`s Milos Raonic.