LONDON — Canadian teenager Felix Auger-Aliassime has recorded one of the biggest wins of his career.
The No. 8 seed from Montreal upset top-seeded Stefanos Tsitsipas of Greece 7-5, 6-2 in the quarterfinals of the Queen's Club grass-court tournament on Friday.
Tsitsipas, ranked sixth in the world, marks the highest-ranked player the 21st-ranked Auger-Aliassime has beaten in his career.
Auger-Aliassime, 18, also beat Tsitsipas in Indian Wells, Calif., earlier this year when the latter player was ranked 10th.
Auger-Aliassime will Feliciano Lopez after the unseeded veteran from Spain beat No. 6 seed Milos Raonic of Thornhill, Ont., 4-6, 6-4, 7-6 (5) later Friday.
The 113th-ranked Lopez, 37, won Queen's Club in 2017.
The age differential between the players will be the greatest in an ATP semifinal or final since the 43-year-old Ken Rosewall defeated 23-year-old American Pat Dupre to reach the Hong Kong Grand Prix final in 1977.
The win against Tsitsipas was Auger-Alaissime's fifth in as many matches against the Greek star dating back to their junior days.
"Whenever I step on court with him, I believe I can win and that's obviously a big plus," Auger-Aliassime told the ATP Tour.
Auger-Aliassime fought off seven break-point chances for Tsitsipas and won 77 per cent of his first-serve points.
Auger-Aliassime has not been broken in three matches this week, holding serve in all 38 games. He has saved nine break points.
The Canadian is looking to make his fourth ATP Tour final of the season. He lost last week to Italy's Matteo Berrettini in the final of the Stuttgart Cup, Auger-Aliassime's tour-level grass-court debut.
Auger-Aliassime is the youngest semifinalist at Queen's Club, a Wimbledon tune-up, since Lleyton Hewitt recorded the feat at age 18 in 1999.
The Raonic-Lopez match couldn't have been much closer. The Canadian won 101 points, while Lopez took 99.
Raonic fought off one match point on Lopez's serve in the tiebreak, but then hit a shot into the net to end it.
Raonic was returning after dropping out of Stuttgart with a back injury prior to a semifinal against Auger-Aliassime.
Also, the fourth-seeded Daniil Medvedev defeated Diego Schwartzman 6-2, 6-2 for a semifinal against Gilles Simon. The French player defeated compatriot Nicolas Mahut 7-6 (5), 5-7, 7-6 (3).
Meanwhile, Andy Murray's comeback after a five-month absence will continue into the weekend after his doubles match at Queen's Club was suspended in the second set due to darkness.
The three-time Grand Slam champion and Lopez won their first set 6-4 and were 5-4 down in the second to British duo Daniel Evans and Ken Skupski when fading light forced a halt to play at the grass-court event.
Murray was playing freely in his second match since undergoing what he hopes was career-saving hip surgery 144 days ago.
It's shaping up to be a busy Saturday for Lopez, as he finishes his doubles match, plays in the singles semifinals and possibly the doubles semifinals straight after that.
Defending champion Marin Cilic and former winner Grigor Dimitrov were both knocked out in the second round on Thursday.
— with files from The Associated Press