The eighth-seeded Sipaeya went down fighting to the big-serving Croat, who will play sixth-seeded Kazakh Alexey Kedryuk in the semifinals after the latter defeated Bellary Open champion and second-seeded Austrian Rainer Eitzinger 6-3, 6-4 in a high-voltage contest.

Unseeded Austrian Philipp Oswald created the other major upset of the day when he beat Slovakian top seed Pavol Cervenak 6-3, 6-2. Oswald will clash with fourth-seeded Israeli Dekel Valtzer in the semifinal after the latter outlasted Slovakian seventh seed Marek Semjan 5-7, 7-5, 7-6 (9-7) in a long drawn battle that lasted almost three hours.

Seesaw battle
Cerovic broke Sipaeya in the second game of the match on his way to a 3-0 lead early. However, it was Sipaeya's turn to return the compliment as he broke Cerovic twice during a four-game winning streak. The seesaw battle continued with Cerovic breaking Sipaeya again in the eighth game.

The Croat opened up a 6-5 lead by holding serve to love in the 11th, including a couple of trademark aces, and then broke Sipaeya in the 12th game to pocket the first set.

In the second set, Sipaeya broke Cerovic in the third game on his way to a 6-4 result to set up the decider.
Cerovic, who had not been at his brilliant best in the second set, made amends in the decider as he excelled from the back court. Struggling with his serve, Sipaeya made Cerovic’s task easier with too many unforced errors. With the Croat getting breaks in the third and eighth games, it was all over for the former national champion.
Earlier Kedryuk, who didn't know how to draw the line between aggression and arrogance, halted Eitzinger's dream run with a 6-3, 6-4 victory in a match which saw some long rallies.

Kedryuk began the match with a double-fault, kept arguing with the chair umpire and linesmen, and threw tantrums as well as his racquet about quite frequently.
Lucky escape
One of those 'missiles' narrowly missed a ball boy standing close to the chair. Upset with a line call, Kedryuk smashed his racquet at the chair, breaking it in the process, and was lucky to escape with only a warning from chair umpire Somnath for code violation.

Kannan-Kedryuk win
In doubles section, India’s Vijay Kannan, pairing with Kedryuk,  moved into the title round with  a 7-6 (7-2), 6-3 win over the Indo-Ukraine pair of Shivang Mishra and Ivan Anikanov.

Results (prefix denotes seeding): Singles, quarterfinals: 3-Ivan Cerovic (Cro) bt 8-Sunil Kumar Sipaeya (Ind) 7-5, 4-6, 6-2; 6-Alexey Kedryuk (Kaz) bt 2-Rainer Eitzinger (Aut) 6-3, 6-4; Philipp Oswald (Aut) bt 1-Pavol Cervenak (Slo) 6-3, 6-2; 4-Dekel Valtzer (Isr) bt 7-Marek Semjan (Slo) 5-7, 7-5, 7-6 (9-7).
Doubles, semifinals: 2-Vijay Kannan (Ind)/ Alexey Kedryuk (Kaz) bt Ivan Anikanov (Ukr)/ Shivang Mishra (Ind) 7-6 (7-2), 6-3; Tushar Liberhan/ Rupesh Roy (Ind) bt 4-Ivan Cerovic (Cro)/ Dekel Valtzer (Isr) 6-4, 6-4.
Quarterfinals: Anikanov/ Mishra bt Pavol Cervenak/ Marek Semjan (Slo) 6-3, 7-6 (8-6); 2-Kannan/ Kedryuk bt Rohan Gide/ Rahil Makharia (Ind) 6-2, 6-1.