Judd Trump overcame a shoulder problem and spirited resistance from non-tour player Adam Duffy to reach the Indian Open last 16 with a 4-3 win.
Trump, 25, had considered withdrawing from the tournament so severe was the pain on Wednesday.
"It wasn't an enjoyable game and I can't really take much from it," said Trump, who now faces Mark Williams.
"The shoulder is better than it was in my first match, though it is still not perfect."
He added: "I don't expect much tomorrow, I will just battle like I did today and see what happens."
Trump had led 3-1 before Duffy came back to take the best-of-seven contest to a decider.
The 2011 World Championship finalist then took a scrappy frame to book a third-round tie with Williams, who edged Peter Ebdon 4-3.
Third-seed Ricky Walden is also through after beating home hope Aditya Mehta 4-2 and now faces China's Tian Pengfei for a place in the quarter-finals.
World number 60 Kyren Wilson caused a shock when he overcame in-form fellow Englishman Ben Woollaston 4-1.