Rio de Janeiro: India's premier shuttler Saina Nehwal suffered a shock exit while Kidambi Srikanth won his group round match in the Rio Olympics here on Sunday.

Saina's defeat was a huge upset against World No.61 Marija Ulitina of Ukraine in her second match of Group G as she was eliminated, losing 18-21, 19-21 at the Rio Centro.

In the men's category, Srikanth outplayed Henri Hurskainen of Sweden 21-6, 21-18 in his group H preliminaries encounter. The only Indian to qualify in the men's singles event had previously beaten Lino Munoz of Mexico 2-0 in his campaign opener.

Ulitina, 24, effected a shock win against the World No.5 and 2012 London Games bronze medallist Saina.

The 26-year-old Indian, a top medal contender, failed to find her rhythm and looked slow as she was not moving well within the court. Saina also conceded a lot of points on misjudgement and was not able to retrieve once the shuttle moved behind her.

Saina started the first game in a dominating way building a 7-1 lead but the 24-year-old Ukrainian soon pulled up her socks levelling the game at 8-8.

Saina just edged past the mid-game interval with a two-point lead. After the interval there was a neck-to-neck fight for every point, levelling the score at 17-17 before the World No.61 took three point of trot.

Saina tried to fight back but Ulitina sealed the game 21-18 in 19 minutes at Pavillion Four of Riocentro.

In the second game, the Indian star shuttler barely managed a slender one-point lead at the mid-game interval.

The second game saw many tough shots and some thunderous body and diagonal smashes by Ulitina.

After the interval, things were equal at 15-15, 18-18 and 19-19 before the Ukrainian clinched two points and the match, ending the Indian's hopes.

Srikanth's performance was diametrically opposite of Saina's.

In a lop-sided first game, the Guntur-born player got off to a brilliant start as he raced away with a 11-2 lead with some solid net play and cross-court smashes before wrapping up the first game in his favour.

The second game was an example of Srikanth's tenacity and patience. By virtue of his exceptional defensive skills, the Sweden player managed to stay in touch with the Indian.

After few exchanges till the mid-half of the second game, the Indian shuttler showed some good skills with the combination of his diagonal shot and down the line smashes to take a 18-15 lead.

In the last few points, there was stiff competition but Srikanth overpowered his opponent to clinch the issue comfortably.