Photos: Saina, Vijender, Jai provide cheer at the Games

The sagging morale of the Indian contingent at the London Games got a much-needed boost when key medal contenders Saina Nehwal and Vijender Singh began their respective campaigns on a promising note.

-London Olympics - Full coverage

Also among the winners on the second day of competitions was Vijender's teammate, Jai Bhagwan, but there were disappointments in store on most other fronts.

Shuttler Saina, among the hot favourites for a podium finish, whipped unheralded Swiss rival Sabrina Jacquet, a quarter-finalist at the last European Championships through which she qualified, 21-9, 21-4 in just 22 minutes.

The 22-year-old Hyderabad stalwart and world No 5, who lost in the quarter-finals at the Beijing Games four years ago, takes on Belgian's Lianne Tan next on Monday at the Wembley Arena.

-Saina kicks-off Olympics campaign on rousing note

Indian boxing's pin-up star Vijender also got off the starting blocks in style. He easily outpointed Kazakhstan's Danabek Sukhanov 14-10 in a late night 75 kg first round bout on Saturday.

-Vijender off to a winning start at London Olympics

"I am delighted to make it through to the next round; he was a tough opponent and now it's onto the next challenge," said the 26-year-old Haryana star.

"I want to go home with a different coloured medal this time," added Vijender, who scripted history in Beijing by becoming the first medal winner in the ring.

Vijender will take on Terrell Gausha of United States in the pre-quarters on August 2.

His teammate Jai Bhagwan also produced a dominating performance and stormed into the pre-quarter-finals of the lightweight (60kg) category to bring cheer to the boxing camp after the early exit of Shiva Thapa in the 56 kg class on Saturday.

-Jai Bhagwan storms into second round of 60kg event

Participating in his maiden Olympics at the age of 26, Bhagwan was in control of the bout from the onset as he thrashed Andrique Allisop of Seychelles 18-8.

Bhagwan will next face Gani Zhailauov of Kazakhstan.

Single sculls rower Swarn Singh Virk and double sculls duo of Sandeep Kumar and Manjeet Singh also stayed in the medal hunt.

But paddler Soumyajit Ghosh, the women shooters and archers put up a flop show yet again.

Swarn Singh held off a late challenge from his South Korea's Kim Dongyong to win the single sculls repechage round and book a berth in the last eight.

Swarn, who had to compete in the repechage round after finishing fourth in the heats on Saturday, clocked 7:00.49s over the 2-km distance, winning the five-man race by more than a boat's length, at the Eton Dorney Rowing Centre.

Lightweight double sculls competitors Sandeep and Manjeet finished fourth in the heats and will compete in the repechage round on Tuesday.

But disappointments continued at the Lord's Cricket Ground, the venue of the archery competition, where the women's team was off target in crunch situations as it lost to Denmark by a point in a see-saw pre-quarter-final battle.

The trio of World No. 1 Deepika Kumari, Bombayla Devi and Chekrovolu Swuro lost 210-211 to the Danish team, comprising Louise Laursen, Maja Jager and Carina Christiansen, and exited from the team event.

Even though the Indians hit more perfect 10s than their opponents, the Danes saved their best for key moments during which the Indians wilted under pressure.

-Women archers blame weather conditions

The Danes hit the bull's eye thrice compared to just once by the Indians, who were hampered by Deepika's indifferent form.

Bombayla, however, seemed in good touch and kept the team in the hunt till the end, getting most of the 10s -- including three in a row, but Swuro fired a poor 5 and then a 6 to let the team down.

The Indians won the first and last sets, but the Danes had the overall lead.

Earlier, the men's team had crashed out at the pre-quarter-final stage on Saturday after losing to Japan.

The archers now will have to look forward to the individual events, starting on Monday.