The boxing ring in the Olympics [Images] on Saturday continued to be India's happy hunting ground as Haryana hurricanes Jitender and Vijender scripted sensational all-the-way victories and booked a berth in the quarterfinals and need one win each to ensure India a medal.

However, Indian athletes continued to put up a disappointing show with discus thrower Vikas Gowda and short distance runner Mandeep Kaur (400m) and the trio of J J Shobha, Sushmita Singha Roy and G G Pramila in hepthathlon falling by the wayside in qualification rounds.

Making his Olympic debut, Jitender Kumar, the 21-year-old dimunitive flyweight boxer from Haryana, swamped Uzbekistan's Tulashboy Doniyorov 13-6 in a 51kg (flyweight) bout marred by frayed tempers this afternoon.

Jitender, who led in all the rounds on Saturday, meets three-time European champion Russian Georgy Balakshin in the last eight on August 20 and gets a chance to avenge his defeat in the 2007 World Championship by just one point.

"It's going to be tough against him. The last time we met it was too close to call and he (Balakshin) managed to sneak past riding on his luck but this time I am better prepared," Jitender said.

"This time I'm not going to spare him. Akhil has beaten him in the past and I'll ask Akhil how to crack him," he added.

Hours later, Vijender thoroughly dominated his bout to tame Angkhan Chomphuphuang of Thailand 13-3 to sail into the quarterfinals of the 75kg category event and a win against Carlos Gongora of Ecuador in quarterfinal would assure him an Olympic medal of whatever hue.

Jitender and Vijender became the second and third Indian pugilists after giant-killer Akhil Kumar (54kg) to reach the quarterfinals.

Jitender displayed maturity beyond his age and won an essentially a tactical battle. He landed the first blow on the  Uzbek and led 4-1 after the opening round. Having established the lead, he protected it even if constant evading did not look glamorous.

Tulashboy became increasingly frustrated and it told on his performance. In the subsequent rounds, the two boxers were grappling each other as much as they were boxing.

Initially struggling to breach the Uzbek's defence, Jitender went for a subterfuge. He threw upper-cuts so that Tulashboy lowered the guard and then unleashed vicious jabs bang on targets to score crucial points.

Though the Uzbek was more aggressive of the two his inability to connect against a fast-moving Jitender did him in and the Indian bagged the lone second round point to stretch his lead.

Tulashboy went all out in the final two rounds but Jitender spent most of the time, bobbing and weaving. And when he went in, he did so with a purpose and the Uzbek could never actually pin him down.

In fact, through the four rounds Tulashboy managed to land just four punches on Jitender  his other two points came from penalty  compared to 11 blows that Jitender successfully unleashed on the Uzbek.

In a lop-sided bout against his Thai opponent, Vijender began on a cautious note and took a 2-0 lead at the end of the first round before going on the offensive.

Though the Thai managed to land a punch on Vijender in the second round, it was too little against the marauding Haryana lad did enough to stretch his lead to 6-1.

The third round saw the Indian dictating terms sending Angkhan scurrying for covers. The Thai's aggression was frustrated by fast movement of Vijender who swung away from his punches.

The Thai never looked like staging a comeback as Vijender ensured his superiority remains intact and in the end, it turned out to be a facile win for the Indian.

Making most of his height advantage and long reach to unnerve the Thai who looked confounded, Vijender unleashed mostly upper cuts and jabs and the rival had no clue as to what was going.

It was a sweet revenge for Vijender, who had lost to the Thai in the Asian Championship in Ulan Bator, Mongolia, and had to be content with silver.

"It was a great bout and Vijender displayed his full bag of tricks. It went just as we had planned," an elated coach Gurbux Singh Sandhu told PTI.

"Vijender was in full control and not for once did he look vulnerable. Whatever we planned bore fruit and I'm proud of the way he fought today," he added.

Asked about Vijender's next bout, Sandhu said, "He has not played against him (Carlos Gongora) but we have certain plans and you will see it in the quarterfinal bout itself."

The track and field events continued to throw up disappointment as Vikas Gowda's Beijing [Images] Olympics campaign wilted in the qualifying round itself with the US-based Indian discus thrower failing to reach anywhere near his personal best on Saturday.

Gowda, who had a similar experience four years ago at the Athens Olympics, hurled the discus 60.69 to finish 11th in Group A and 22nd overall, a performance way below his personal best and national record of 64.96m.

In women's hepthathlon, Pramila, Shobha and Sushmita could not even cross the qualifying round for the final line-up of 15.

True, Pramila on Saturday came up with the best show among the three Indians to finish 28th but it was not good enough for a place in the final. Shobha and Sushmita came 30th and 33rd respectively.

Pramila secured 983 points in 100m hurdles, 903 in high jump, 639 in shot put, 894 each in 200m and long jump, 692 in javelin and 777 in 800m to finish with a total of 5771.

Shobha totalled 5749 (1033+795+732+922+922+735+725), while Susmita aggregated 5705 (963+867+613+948+948+663+808). 

Ukrainian Nataliia Dobrynska won the gold with an aggregate of 6733, while compatriot Lyudmila Blonska (6700) grabbed silver and American Hyleas Fontain (6619) bagged the bronze in the event.