Rio de Janeiro: Star shuttler P.V. Sindhu entered the quarter-finals of the women's singles event at the on going Rio Olympics by defeating Tai Tzu-ying of Chinese Taipei in straight games here. Sindhu dominated right from the start to defeat her highly rated opponent 21-13, 21-15 within 40 minutes in the pre-quarterfinal clash at Court 2 of the Riocentro Pavilion 4 on Monday. Before Monday's match, Tzu-ying enjoyed a 4-2 advantage in head to head encounters against Sindhu. But the 21-year-old from Hyderabad was in superb form and dominated her opponent throughout the match. But Sindhu is expected to face a much tougher challenge in last eight stage as she will now face World No.2 Wang Yihan of China. "I was basically alert to everything. There was not a particular strategy. You have to be alert on what to play and when to play. My opponent was a very tricky player. She was not leaving any shuttle, even though I was getting points or I was leading. Overall it was a good game and she played well," Sindhu said after the match. "The shots were a mix of everything, not only on the body. Sometimes in the second game, I was hitting out on midcourt shots. But I was alert to everything, getting ready for the next point. Overall I didn't take it easy," she added. The 21-year-old from Hyderabad admitted that Wang Yihan will be a difficult opponent, but is confident of creating an upset. "Tai Tzu-ying was giving very good flicks. She was attacking very good and even her drops were very good. But eventually it was a good win for me. I hope tomorrow is also a great one," Sindhu said. "But tomorrow is a tough game as I am playing World No 2. I will give my best and play my game. Strategy-wise I will discuss with my coach. I have played against her several times but there has been a long gap since then." The opening game witnessed long rallies with Sindhu forcing the early advantage thanks to her powerful smashes and unforced errors by Tzu-ying. Tzu-ying gave Sindhu a tough fight in the early stages. Despite conceding the lead on several occasions, she drew level every time before the Indian forced a 11-6 lead by the mid-game break. The Taiwan shuttler continued to fight hard with her deceptive drop shots and cross court smashes causing problems for Sindhu. Sindhu seemed to lose her rhythm a bit after the break as Tzu-ying reduced her lead to 12-10. But the Indian soon recovered to bolster her lead to 19-13 before a couple of unforced errors handed her the first game. Sindhu forced the early advantage in the second game as well with Tzu-ying continuing to fight hard. Tzu-ying was troubled by the draft in the second game which saw her conceded a couple of unforced and allowed Sindhu to take a 6-3 lead. But to her credit, the Taiwan shuttler took three points on the trot to draw level. But a powerful forehand smash by Sindhu and more unforced errors by Tzu-ying enabled the Hyderabad girl to score five consecutive points and open up an 11-6 lead at the break. Sindhu kept up the pressure after the break with four back to back points increasing her lead to 15-7. Tzu-ying rallied to reduce the Indian's lead to 15-11 before she committed two unforced errors to lose the momentum. With Sindhu serving for the match at 20-12, Tzu-ying managed to save three match points and pull back to 20-15. But Sindhu did have to wait long to celebrate as another unforced error by Tzu-ying handed her the game and the match.