Haroon Khan, 19, was overlooked by England and Britain
Amir Khan's younger brother, Haroon, stopped Tanzanian opponent Sunday Elias in round three of their 52kg bout to start to his Games campaign in style.
The junior Khan, boxing for Pakistan, held a 12-1 lead at the stoppage.
"This is a big opportunity for me to prove the critics wrong in England and I've done that," said Khan, who was overlooked for Britain's elite squad.
He could meet either of two GB elite squad members, Tommy Stubbs or Andrew Selby, later in his flyweight category.
"Haroon can be better than Amir. If he puts 100 per cent into his training he can do it," said his father, Shah Khan.
"He's got to fend for himself now. He's got a lot to prove and that's going to make a difference to him.
"Fighting for Pakistan has given him the hunger. He will probably go to the Asian Games with them in November, then we will see what happens from there."
The 19-year-old's elder sibling, Amir, won a lightweight silver medal at the 2004 Athens Olympics and is now the light welterweight world champion.
The first day of wrestling in Delhi saw Indians complete a clean sweep of the gold medals available, but Hassene Fkiri of Australia put in one of Tuesday's more remarkable performances.
Fkiri, left, was disqualified from his 96kg final
According to the AFP agency, coaches and officials confirmed that Fkiri - who lost the 96kg Greco-Roman final to India's Anil Kumar - had been disqualified after making an obscene gesture to the judges.
After Fkiri had allegedly shown his middle finger to the panel, his coach, Kuldi Bassi said: "I didn't actually see anything myself but someone else told me he saw it.
"He's a very nice person normally, (but) Kumar upset him a bit and was pulling his neck.
"I told him that was what was going to happen and I think he just lost control. It's very sad and it's bad for the country."
It was unclear whether Fkiri had been disqualified for dangerous play during the bout, or had lost his silver medal as a result of the gesture.
Malaysia have marked out England as potential obstacles to gold in the team badminton, despite continuing their march towards defending their title.
They recorded a third consecutive whitewash in the team event, beating Nigeria 5-0, to reach the quarter-finals on Tuesday.
"It was really good to win for the team," said former all-England champion Muhammad Hafiz Hashim.
"We really want to win this title again, but I think that England, India and Singapore will all be tough competitors."
And inside the tennis arena, India continued to assert their dominance, moving to a record of seven wins from eight ties.
Doubles pair Leander Paes and Mahesh Bhupathi combined to beat Sri Lanka's Dineshkanthan Thangarajah and Amresh Jayawickreme 6-3 6-3, while Somdev Devvarman defeated Devin Mullings of the Bahamas 6-4 6-2 in the men's singles
Women's pair Nirupama Sanjeev and Poojashree Venkatesha beat Irufa Mahir and Maleela Solih of the Maldives 6-0 6-1.
Crowds at the tennis have been steadily increasing, with 1,000 fans making their way to the 5,600-seat RK Khanna stadium to see Paes and Bhupathi win.