New York: Grigor Dimitrov rallied for a shocking upset of 20-time Grand Slam champion Roger Federer at the US Open, the lowest-ranked New York semi-finalist in 28 years advancing to face Daniil Medvedev.
The 78th-ranked Bulgarian, who had dropped all seven prior meetings with Federer, on Tuesday made a dramatic fightback to defeat the Swiss third seed 3-6 6-4 3-6 6-4 6-2 at Arthur Ashe Stadium and will face Russian fifth seed Medvedev in Friday's semis.
Serena Williams earned her 100th win at the US Open with a brutal 44-minute demolition of Wang Qiang, firing an ominous warning to rivals in her pursuit of a record-tying 24th Grand Slam title.
Six-time US Open champion Williams on Tuesday dismantled Chinese 18th seed Wang 6-1 6-0 in a complete mismatch that was the quickest at this year's tournament to set up a semi-final clash with Ukrainian trailblazer Elina Svitolina.
Williams brought up a century of US Open wins to move to within one of the all-time leader Chris Evert.
"It's really unbelievable, literally. From when I first started here, I think I was 16, I didn't think I would ever get to 100. I didn't think I would still be out here," Williams said.
The 37-year-old American is seeking a 24th major title to match Margaret Court's longstanding record, and smacked 25 winners against first-time Slam quarter-finalist Wang, who failed to hit a single one.
The 27-year-old Wang had not lost a set during her best Slam run that included a defeat of reigning French Open champion Ashleigh Barty in the last 16, but she was powerless to stop a Williams onslaught at Arthur Ashe Stadium.
Fifth seed Svitolina defeated Britain's Johanna Konta 6-4 6-4 to become the first Ukrainian to reach the US Open semi-finals, matching her run to the last four at Wimbledon in July.
Svitolina watched a pair of match points pass her by at 5-3 on her opponent's serve as Konta gamely fought to stay alive, but the Ukrainian closed out victory in the following game.
Svitolina had already knocked out two-time former champion Venus Williams and 2017 runner-up Madison Keys and is in a class of her own as the only Ukrainian woman to reach this stage at a major.
She will attempt to emulate Andrei Medvedev as just the second Ukrainian to play in a Grand Slam final. Medvedev lost the men's 1999 Roland Garros final in five sets to Andre Agassi.
Williams, the lone former Grand Slam champion remaining in the draw, has defeated Svitolina in four of five previous meetings, although the latter won their most recent encounter at the 2016 Rio Olympics.
Konta, who took out third seed and 2016 runner-up Karolina Pliskova in the last 16, was denied in her bid to be the first British woman to make the US Open semis since Jo Durie in 1983. Swiss 13th seed Belinda Bencic faces good friend Donna Vekic, the 23rd seed from Croatia, in the other last-eight clash.
Fifth seed Medvedev's 7-6 (8/6) 6-3 3-6 6-1 triumph sent him into a Friday matchup with Grigor Dimitrov.