LONDON - China's Ding Junhui saw off debutant Zak Surety 10-7 to reach the second round at the World Snooker Championship for the first time in five years.

Ding, 38, opened the match 4-0 on Monday and set up a 6-3 lead before Tuesday's second session. Although world No 73 Surety launched a strong comeback to win three of four frames since the match's resumption, 10th seed Ding held his nerve to take the win.

Ding, with 15 ranking titles under his belt, acknowledged that his opponent's form put some pressure on him, but said he managed to focus on his own game and tried his best to score whenever he got a chance.

Elsewhere, 22-year-old Si Jiahui reached the last 16 for the third year in a row after beating David Gilbert 10-6. He now faces either Mark Selby or Ben Woollaston.

Seven-time world champion Ronnie O'Sullivan, who had been absent from the tour for a few months due to medical reasons, fought hard to lead Ali Carter 5-4.