The Indian challenge in the singles draw at Chennai Open ended with Rohan Bopanna going down in straight sets to fifth seed Gilles Muller of Luxemborg at the SDAT stadium on Thursday.

Prakash Amritraj had lost his second round match to Radek Stepanek on Wednesday.

Bopanna, who had the biggest scalp of his career on Tuesday when he beat world number 90 Cyril Saulnier, lost 3-6, 4-6 to Muller in the second round in 66 minutes.

Earlier, Kristof Vliegen of Belgium caused the biggest upset of the tournament by defeating number six seed Rainer Schuettler of Germany [Images] 6-2, 6-4.

Top seed Ivan Ljubicic overcame a stiff challenge from Czech Jiri Vanek to win 6-3, 3-6, 6-3.

Muller had an easier match than the scoreline suggests and the difference between their world rankings clearly showed on court. The 22-year-old from Luxemborg, ranked 76th, didn't concede a single break point in the match to Bopanna, ranked 266th.

Bopanna, put on centre court for the first time in the tournament, could not penetrate his opponent's strong serve and was left scurrying by the baseline. His serve bailed him out of trouble most of the time, but with Muller not giving an inch on his games, he only had to lose two of he eight break-points to mark his exit.

Such was Muller's domination, that out of the 10 games he served for in he match, he won five of them on love.

Bopanna, whose big game had helped him beat Saulnier so convincingly, was efinitely a few notches below and just seemed to run out of confidence against the quality tennis of Muller.

"I was trying to push him back, play with a lower spin and didn't give him too much pace to work around," said Muller, on his win.

Though the Indian held the set till 4-4, he served a double-fault on break point to have Muller serve for the match.

Muller will meet Croatia's Ljubicic in the quarter-finals, while Bopanna and Amritraj will play their first round doubles later in the evening.

Ljubicic had to undergo another tough test against the experienced Vanek to enter the last eight.

The Czech, after losing the first set 3-6, came back well in the second to take a 3-0 lead. Ljubicic wasn't able to keep up with Vanek's pace and, as he said later, was finding it difficult to spot the ball under the lights.

"I played the first game in the night. This time it started in the evening and the lights were coming on. So it was not easy to see the ball," said the Croat world number nine.

The third set also ran close, with most of the games going to deuce, but Vanek finally cracked under pressure to concede the set 3-6.

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