PARIS—Before the French Open, Tamara Zidansek had never advanced past the second round at any Grand Slam. The former snowboarder has now become the first woman from Slovenia to reach the semifinals at a major tournament. Spurred on by the vocal support of her coaching team on Court Philippe Chatrier, the 85th-ranked Zidansek defeated Spanish rival Paula Badosa 7–5, 4–6, 8–6 Tuesday at the clay-court tournament. The French Open is the only remaining Grand Slam where tiebreakers are not played in the last set. Wimbledon recently installed tiebreakers at 12-12 in the final set. After splitting the first two sets, Badosa violently threw her racket in anger at the changeover after Zidansek held for a 6–5 lead in the third. She regained her composure but Zidansek then saved three break points to take a 7–6 lead and converted her second match point with a big forehand in the next game. …