Shanghai, Oct 11 (IANS): Playing in only his third quarterfinal on the ATP Tour, Czech star Tomas Machac brought to an end Carlos Alcaraz’s 12-match winning streak for the season, stunning the year's French Open and Wimbledon winner on Thursday to reach the semifinals in the Shanghai Masters.

Machac, playing in his quarterfinal in the Shanghai Masters, produced some of his most blistering tennis to neutralise the threat of the World No. 2, prevailing 7-6(5), 7-5. In a match where both players produced high-quality tennis, the 23-year-old found another gear to record his second win over a Top-5 opponent (Djokovic, Geneva SF).

The Czech player led by a set in his first meeting with Alcaraz at the Davis Cup last month, but was forced to retire once the Spaniard had levelled the match. Machac made no mistake this time, however, striking 20 winners in a superb opening set before dismantling Alcaraz's serve in the third game of the second.

Alcaraz showed signs of a fightback after he had retrieved the break, but the Czech maintained his composure to seal victory in one hour and 54 minutes, winning 100 per cent (7/7) of points at the net in the second set, according to Infosys ATP Stats.

Machac, who opted to play an ATP Challenger Tour event instead of the Shanghai Masters last year, is now up to No. 25 in the ATP Live Rankings. He will face World No. 1 Jannik Sinner for a spot in the final after the Italian eased past Daniil Medvedev to reach his first Shanghai semifinal.

After becoming the fourth lowest-ranked semifinalist in Shanghai tournament history, Machac will bid to level his Lexus ATP Head2Head series with Sinner after falling to a 6-4, 6-2 defeat in the quarter-finals of the ATP Masters 1000 in Miami.