Huelva (Spain), Dec 18 (IANS): On a historic day for country's badminton, India were assured of at least two medals at the 2021 BWF World Badminton Championships after former world No 1 Kidambi Srikanth and young Lakshya Sen entered the men's singles semi-finals of the event, here on Friday.

However, it wasn't a good day for defending women's champion PV Sindhu, who lost to familiar foe Tai Tzu Ying in the women's singles quarter-finals and was knocked out of the tournament.

The top-seeded Tai Tzu defeated Sindhu 21-17, 21-13 in the women's singles quarter-finals, which lasted 42 minutes, to end the Indian badminton ace's title defence.

Reigning world champion Sindhu had a nervous start with Tai Tzu rushing to the 9-3 lead in the first game. She amped her pace with aggressive cross-court shots but the Chinese Taipei shuttler was clever with her deceptions and managed to win the opening game.

In the second game, Sindhu gave better competition to her opponent but could not quite take a sizable lead at any point. Tai Tzu frequently employed her drop shots to catch the Indian out and after being tied 12-12 in the second game, the Chinese Taipei shuttler surged ahead to wrap up the match.

This is the first time that world No. 1 Tai Tzu has progressed past the quarters at the badminton world championships. She had defeated Sindhu in the semi-finals of the Tokyo Olympics earlier this year.

Meanwhile, ace Indian shuttler Srikanth beat Dutch badminton player Mark Caljouw 21-8, 21-7 to advance to the semi-finals in men's singles.

The 12th seeded Indian used his cross-court smashes to perfection and gave Caljouw no chance, winning the quarter-finals quite comfortably in just 26 minutes.

This is Srikanth's first semi-final appearance at the world championships. With this, he has now ensured his first and India's 11th medal at the World Championships.

Youngster Lakshya Sen also made his way into the semis after a hard-fought 21-15, 15-21, 22-20 win over China's Zhao Jun Peng. Lakshya saved a match point at 19-21 and won two more points to assure a bronze medal.

Now, Lakshya and Srikanth will face each other in the last four, which means that India will win at least a bronze and a silver medal -- since one will go through to the final.

This is the first time that India will have two medals in the men's singles in the same edition of the badminton world championships. India had only won two men's singles medals -- Prakash Padukone (bronze in 1983) and B Sai Praneeth (bronze in 2019) across world championships history until now.

However, HS Prannoy could not join his compatriots in the last four as he lost 21-14, 21-12 to Singapore's Loh Kean Yew, who had beaten Viktor Axelsen in the first round.