Kalaburagi, Nov 30 : Aryan Shah, the country's top junior tennis player who had made it to the main draw after two tough qualifying rounds, scored an upset victory over fourth-seeded Sidharth Rawat in a Round of 16 clash in the ITF Kalaburagi Open here on Thursday. The 18-year-old, after being on the brink of defeat twice in the match, won a hard-fought battle 4-6, 7-6(4), 7-6(3) to enter the quarterfinals at the Chandrashekhar Patil Stadium here on Thursday. Aryan Shah had impressed during his first-round encounter against Adil Kalyanpur. Apart from Aryan, three other Indians including the man in form and fifth seed Ramkumar Ramanathan, sixth seed Rishab Agarwal, and giant killer Manish Sureshkumar also made it to the last eighth stage. Second seed Matsuda Ryuki of Japan along with his countrymates Ryotaro Taguchi and Seita Watanabe and seventh seed David Pichler of Austria were the other quarterfinalists. Considering the prowess of both the players, the Aryan-Sidharth match was expected to be an exciting affair. Both began by breaking each other's service. The younger opponent took time to settle, committed a few unforced errors and lost serve in the fifth game which cost him the first set. The second set too began on a similar note but this time the fourth seed was quick to grab an opportunity and went 3-1 up with another break in the third game. Serving for the match at 5-4 and two match points up, Sidharth, who is ranked over 1000 places above Aryan, hit the ball out thrice to lose his serve which changed the momentum of the match as Aryan who had qualified for the US Open Junior Singles this year, hit some brilliant down the line winners while taking the set into the tie-breaker, where he won 7-4. Aryan was a break-up early in the deciding set but Sidharth, the Indian Davis Cup team member not only returned the favour but also went 3-2 up to set up a similar situation and was serving for the match at 5-3. However, with three good winners from Aryan, he lost the serve as the set went to the wire with Aryan winning the tie-breaker at 3 in a match that lasted for two hours and 49 minutes. Meanwhile, Ramkumar was made to toil by wild card entrant Kabir Hans before registering a 7-5, 3-6, 6-2 win. Ramkumar who is just back from an ITF M25 victory, struggled with his game in the initial part of the set as he was 0-3 down and later 2-5 down. Using his big serve and a strong forehand, the Indian David Cup team member won five games in a row to take the first set. Achieving a crucial break in the fourth game, Kabir levelled the match scores to 1-1. Ramkumar dominating the final set raced to a 5-0 lead before Kabir put in a semblance of a fightback by winning the next games but could not stop the senior player from taking the match. Results (Indians unless mentioned, seeding in parenthesis) Men's Singles (Round of 16): 7-David Pichler (AUT) bt Harrison Adams (USA) 7-6 (6), 6-3; 5-Ramkumar Ramanathan bt Kabir Hans 7-5, 3-6, 6-2; Manish Sureshkumar bt Q-Bharath Nishok Kumaran 6-1, 6-0; Seita Watanabe (JPN) bt Rishi Reddy 6-2, 6-3; 6-Rishab Agarwal bt WC-Manish Ganesh 6-1, 7-6 (1); Q-Aryan Shah bt 4-Sidharth Rawat 4-6, 7-6 (4), 7-6 (3); 2-Matsuda Ryuki (JPN) bt Raghav Jaisinghani 6-2, 6-0; Ryotaro Taguchi (JPN) bt 8-Karan Singh 7-5, 6-1. Doubles (Quarterfinals): Karan Singh/Parikshit Somani vs. 2-David Pichler (AUT)/Nitin Kumar Sinha 4-2 (unfinished); Rishab Agarwal/Bharath Nishok Kumaran bt Sai Karteek Reddy Ganta/Kabir Hans 4-6, 6-4, 10-8; Adil Kalyanpur/Sidharth Rawat bt 3-Taisei Ichikawa (JPN)/Seita Watanabe (JPN) 6-1, 6-4; Ryuki Matsuda (JPN)/Ryotaro Taguchi (JPN) bt WC-Aryan Shah/Ranjeet Virali-Murugesan 6-2, 3-6, 10-5. /IANS