Kristyna Pliskova battled back from a set down against wildcard Svetlana Kuznetsova to reach her first semi-final in nearly two years at the Samsung Open. The Czech also held off a late rally from her Russian opponent to clinch a hard-fought 4-6 6-3 7-5 victory in two hours and eight minutes in Lugano. After evening up the scoreline with a single break of serve in the second set, Pliskova edged ahead early in the decider – only for Kuznetsova to draw level again at 4-4. Unfazed, the world number 101 continued to apply the pressure and claimed a crucial break three games later, going on to serve out the match to love. She will now take on 17-year-old Iga Swiatek in the final four after the Wimbledon junior champion beat Vera Lapko in three sets. The Pole recovered from a set and a break down to eliminate the tournament’s last remaining seed 4-6 6-4 6-1. After missing 10 break points in the opening set, Swiatek found her form in the second to help her secure a place in her first WTA Tour semi-final. The other semi-final will be contested by Fiona Ferro, who ousted Stefanie Voegele 7-5 7-6 (5), and Polona Hercog, who beat Veronika Kudermetova 6-4 6-1. At the Copa Colsanitas in Bogota, Colombia, number six seed Amanda Anisimova won through to the last four after dismissing Maria Camila Osorio Serrano in a battle of the teenagers. The 17-year-olds took a set each before the American surged ahead with three breaks in the decider to triumph 6-2 1-6 6-3. Anisimova will meet Beatriz Haddad Maia in the semi-final after the Brazilian qualifier upset number seven seed Sara Sorribes Tormo. Haddad Maia converted 10 break points in a back-and-forth match to prevail 6-7 (6) 6-2 6-3 after two hours and 45 minutes. Meanwhile, Australia’s Astra Sharma moved into the first WTA semi-final of her career by defeating lucky loser Sara Errani 6-1 7-5. And number 11 seed Lara Arruabarrena secured the other spot in the last four by dismissing number five seed Tamara Zidansek 6-4 6-2.