Buenos Aires: Juan Monaco rewarded fans chanting his name by outlasting Luis Horna of Peru 4-6, 6-2, 6-3 to reach his first semifinals of his hometown Copa Telmex on Friday.Meanwhile, two other unseeded players, Diego Hartfield of Argentina and Alessio Di Mauro of Italy made their first ATP semifinals ever.Horna, who knocked out top-seeded David Nalbandian in the round robin, fell short of the same level, squandering a 2-0 lead in the third set to the delight of about 5,000 spectators at the Buenos Aires Lawn Tennis Club."The match was very difficult," Monaco said. "We both made our mistakes but I never gave up and just tried to put more effort into it at the end."Horna made the only break of the first set in the ninth game. Monaco paid him back in a long fourth game of the second set, and closed it with another service break. Trailing 2-0 in the third set, Monaco won five straight games with precision shots from the baseline, and put away Horna, who won his second career title this month in Vina del Mar, Chile.Wild card Hartfield beat Nicolas Devilder of France 6-4, 7-5, and the 29-year-old Di Mauro put out Albert Montanes of Spain 1-6, 6-4, 6-2 in quarterfinals."This was important for me. It's the first time I've ever made the semifinals," Hartfield said.Hartfield carried a quick 3-0, two-break lead to win the first set 6-4. He broke in the opening game of the second but lost it when he served for the match at 5-4. He immediately broke Devilder for a fourth time, and served out.Di Mauro won the first game then Montanes reeled off the next six.At 2-2 in the second set, Montanes committed two double faults to lose serve, and Di Mauro retrieved some difficult shots to take the set. Montanes tired in the third set while Di Mauro pressed on to win it easily.