Ghosal, who made history last year by becoming the first Indian ever to make the last 16 of the world championship, faced 15th seed Alister Walker, the world No15 from Botswana whom he had never beaten before.
The 27-year-old defied the world rankings at the National Squash Centre - and denied his opponent a place in the last 16 for the first time in six years - by beating Walker 11-7, 11-5, 7-11, 11-7 in 55 minutes.
After scoring a significant upset in Wednesday's second round of the AJ Bell PSA World Squash Championship in Manchester, unseeded Kolkata-based Saurav Ghosal said: "I'm not only doing for me, but also for India."
"I'm happy to win today. I played well in the first two games, I was controlling the pace and trying to make him play in my strength, and was taking as much as I could the ball to the back to go pass him and take the volley away from him - he is so good on the T," said Ghosal.
"In the fourth, he had the confidence from winning the third. But I got it back and went 7-2 up - but it was a hard battle to try and close it off," he said.
When asked if he felt he could push through and make the last eight for the first time, Ghosal said: "If I was able to do so, yes, it would be huge for India. Dipika (Pallikal) was the first ever to reach the quarters, but never has a male player reached that stage."
"And in my view, I'm not only doing it for me, but it's also for India - for all those players that are coming after me. If my results can help and popularise the sport then the impetus will carry on and maybe one day we will have 15 Indian players in the main draw of the World Champs," he said.
Ghosal, the world No17, will line up against fellow non-seed Henrik Mustonen, the 22-year-old Finn who celebrated his first ever appearance in the second round with a shock victory over England's No7 seed and former semi-finalist Peter Barker.
Londoner Barker slipped midway through the third game after leading 2-0 and after losing the game, conceded the match as the result of a calf injury.
--IBNS (Posted on 30-10-2013)