Unfazed by the coup back home, Thailand's Tamarine Tanasugarn continued her good work to book a quarter-final berth at the US $175,000 WTA Sunfeast Open in Kolkata on Wednesday.

Tansugarn got past the United States' Abigail Spears, winning 2-6, 6-3, 6-2 after a two-hour battle, to march into the last eight where she will take on either top seed Martina Hingis [Images] or Israel's Tzipora Obziler who play later in the evening.

Thailand's Army Commander-in-Chief General Sondhi Boonyaratkalin wrested power from Prime Minister Thaksin Shinawatra on Tuesday in a bloodless coup and soldiers and tanks patrolled the streets of Bangkok, the capital, where an uneasy calm prevailed.

Spears, who got special exemption for the tournament, took the opening set by breaking the 29-year-old Tanasugarn in the second, sixth and eighth games.

The Thai girl, who began the set in the style, demolishing Spears in the very first game, failed to keep up the momentum and surrendered the first set in 29 minutes.

However, in a virtual replay of Tuesday's outing against sixth seeded Estonian Kaia Kanepi, Tanasugarn upped the ante in the second set and opened a 2-0 lead after breaking Spears in the first game.

Spears fought back and snatched Tanasugarn's serve in the fourth game, but the Asian, who has a career high world ranking of 19, took the next three games to go ahead 5-3.

Though Spears broke Tanasugarn in the eighth game, the Thai broke back in the ninth to pocket the set.

The third set was completely one-sided as the higher ranked Thai girl broke in the sixth and eighth game to seal the match.

In the post-match media meet, Tanasugarn said she called home last night and found that "things were peaceful."

"I think every country has its own share of problems. But I thought instead of worrying, I would rather concentrate on the match," she said.

Upbeat after her win, the world's 124th ranked player said, "I have a feeling that I play my best tennis in India."

On her possible clash against Hingis, she said, "I have to play a doubles match later in the day. And I am concentrating on that. I take one match at a time."

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