Kevin Anderson of South Africa hit 12 aces and saved all five break points to overcome American Jack Sock, 6-3, 6-4, in the Citi Open semifinals at Rock Creek Park Tennis Center in Washington on Saturday. The South African reached his first ATP World Tour final since August 2015, when he beat Pierre-Hugues Herbert for the Winston-Salem Open title. Anderson will face fifth seed Alexander Zverev, who defeated second seed Kei Nishikori, 6-3, 6-4, in the other semifinal Saturday night. A frustrated Sock departed after facing his second big server in as many matches on the speedy Stadium Court. All week, players had called the Citi Open's courts the fastest on tour — humidity smooths out the grittiness of the cement — and it took Sock a few moments to adjust to Anderson's pace. He won just one point of the first 10. "He played really well," Sock said. "Pretty shocking tennis court. I don't think I'll be back at this tournament, probably, in the future. Probably the worst court of the year. Speed, bounces, everything. Pretty shocking." After reaching the third ATP 500-level final of his career, Anderson explained that the accomplishment makes him feel like he is finally back in top form. As a reward, he ended early enough Saturday that, for the first time all week, he was possibly able to go out to dinner. "Today I actually went back on the court for like five or 10 minutes to practice a couple of things," he said, after having played two matches in the span of 18 hours to get to the semifinal, one of which ended at midnight, "but that's very, very rare." On the women's side, Ekaterina Makarova held off Oceane Dodin, 3-6, 6-3, 6-4, to advance to the final, where she will face the winner of Julia Gorges and Andrea Petkovic. In the women's doubles championship, Shuko Aoyama of Japan and Renata Voracova of the Czech Republic defeated Eugenie Bouchard of Canada and Sloane Stephens of the United States, 6-3, 6-2.