Eastbourne - Novak Djokovic overcame a spirited challenge from Donald Young, beating the American 6-2, 7-6 (11/9) on Thursday to claim the first of the semi-final places at the Eastbourne pre-Wimbledon event.
The Serb top seed, competing during the week before Wimbledon for the first time in seven years, saved a pair of set points in the second set before finally putting Young away after a lengthy tie-break.
The former world number one is rebuilding for Wimbledon after a poor past year by his world-class standards and is pointing toward the grass court major as an immediate goal.
Djokovic, who took a wild card into the tournament on the English south coast, is the second-highest-ranked men's player ever to compete at Eastbourne behind then-number two Marcelo Rios in 1998.
With the rest of the field a round behind after two days of rain interruptions, organisers were playing catch up and praying for better weather.
Fourth seed and title-holder Steve Johnson finished off his contest with Italian qualifier Thomas Fabbiano, advancing 6-3, 5-7, 6-4.
Second seed Gael Monfils dispatched Briton Cameron Norrie 6-3, 6-2 while number three John Isner staged a comeback to defeat Dusan Lajovic 3-6, 7-6 (7/2), 7-6 (7/4).
Australian Bernard Tomic surprised sixth seed Mischa Zverev 6-3, 6-2 as Richard Gasquet, seeded seventh, beat Kevin Anderson 6-4, 6-4.
Results from the ATP and WTA grass-court tournament at Eastbourne on Thursday (x denotes seeding):
Men
Quarter-finals
Novak Djokovic (SRB x1) bt Donald Young (USA) 6-2, 7-6 (11/9)
Second round
Steve Johnson (USA x4) bt Thomas Fabbiano (ITA) 6-3, 5-7, 6-4
Daniil Medvedev (RUS) bt Robin Haase (NED) 4-6, 6-1, 6-2
Richard Gasquet (FRA x7) bt Kevin Anderson (RSA) 6-4, 6-4
John Isner (USA x3) bt Dusan Lajovic (SRB) 3-6, 7-6 (7/2), 7-6 (7/4)
Bernard Tomic (AUS) bt Mischa Zverev (GER x6) 6-3, 6-2
Gael Monfils (FRA x2) bt Cameron Norrie (GBR) 6-3, 6-2
Women
Third round
Caroline Wozniacki (DEN x6) bt Elena Vesnina (RUS x12) 6-1, 6-2
Karolina Pliskova (CZE x3) bt Peng Shuai (CHN) 7-6 (7/3), 6-4
Simona Halep (ROM x2) bt Tsvetana Pironkova (BUL) 6-7 (6/8), 7-6 (7/4), 7-5
Svetlana Kuznetsova (RUS x7) bt Kristina Mladenovic (FRA x9) 6-4, 2-6, 6-3
Second round
Lauren Davis (USA) bt Agnieszka Radwanska (POL x8) 7-6 (7/1), 6-1