Panghal, who won the Asian Games gold medal last year, defeated Korea's Kim Inkyu in a unanimous decision. He came into the tournament on the back of a gold at the Strandja Memorial Tournament in February in Bulgaria.
This was his maiden international competition since moving up to 52kg from the 49kg division earlier this year. Panghal had won a bronze in the 2015 edition of the event.
However, national champion Deepak Singh (49kg) and Kavinder Singh Bisht (56kg) signed off with silver medals after close losses.
Up against a lanky opponent, who was willing to play the waiting game, Panghal started in his usual aggressive style.
The strategy of stumping rivals with relentless attacks paid off against Inkyu and the Korean simply had no answer to Panghal's aggression.
The Indian managed to corner his rival quite often and his solid defences thwarted the feeble attempts at connecting by Inkyu.
Earlier, at the end of Deepak's highly contentious split loss to Nodirjon Mirzahmedov of Uzbekistan, the Indian contingent handed the referee the yellow card meant for seeking a review, which was introduced in the tournament on a trial basis this year.
However, India's High Performance Director Santiago Nieva told PTI that the gesture was merely to highlight "how wrong" the decision was.
"We cannot get the decision changed. Just a protest here," he said.
"The system will officially start in the world championships," added national coach C A Kuttappa.
Bisht, on the other hand, also lost to an Uzbek in Mirazizbek Mirzahalilov, a unanimous decision. The boxer from Uttarakhand fought with a bandage over his right eye but did not back down from going for the offensive.
The aggressive approach resulted in his wound, sustained in the semifinals, opening up just a minute into the third round. This made Bisht slightly defensive and allowed the Uzbek to edge ahead.
Earlier, Deepak also put up a gutsy performance that failed to find favour with the judges.
It was a bout in which both the boxers were mostly looking to counter-attack. Deepak's focus was getting his straight punches across, while Mirzahmedov looked to connect right hooks occasionally.
The Indian was a clear winner in the opening round but Mirzahmedov came back strongly in the second.
The Uzbek turned a shade defensive in the last three minutes, which gave Deepak a chance to assert himself. However, the final outcome was in favour of the Uzbek, much to the surprise of the Indian camp.
Under the Bout Review Process for contentious decisions, teams are handed yellow cards at the beginning of their respective bouts. Coaches got a minute after the fight to appeal against a decision.
A slow motion footage of the bout is then reviewed by an observer, who decides the merits of the appeal. In case the final decision does not favour the team concerned, the national federation has to pay USD 1,000 as penalty.
The system is part of the International Boxing Association's attempts at streamlining the decision-making process which has been under scrutiny for a while now