National champion Pankaj Advani notched his fourth straight victory, but fellow Indians Aditya Mehta and Sourav Kothari crashed to defeats as the preliminary league of the IBSF World Under-21 snooker championship reached the final stages in Taupo, New Zealand, on Monday.

Pankaj smoothly moved past Adam Kinghorn of Australia with a 4-1 (40-51, 112-12, 77-32, 67-61, 64-19) scoreline to remain the only unbeaten player in the seven-man Group F and is almost certain to advance to the knockout stage that comprises top four players from each of the eight groups.

The 18-year old from Bangalore, with two more matches in hand, is ahead of Albert Kenny of Ireland and Jamie O'Neill of England, who have four wins from five outings.

The fourth contender from this group is Nisar Ahmed Saif of Qatar, who has won three of his five matches.

Aditya, the 17-year old from Mumbai, who had won all four previous matches in Group D, tasted his first defeat when he went down to Tain Pengfei of China 1-4 (11-94, 19-80, 38-71, 75-30, 43-72). The Chinese player had two good breaks of 66 and 52.

Despite the loss, Aditya remains in contention for a berth in the Round of 32 with a 4-1 win-loss record as against Mark Allen's (Northern Ireland) 5-5, Pengfei's 5-4 and Jamie Jones' (Wales) 6-3.

However, the fate of Sourav, the 18-year old from Kolkata, hangs in balance as he lost his fourth match in six outings, being defeated by Alex Davies of England 2-4 (70-42, 37-83, 57-70, 8-87, 92-31, 70-49) in Group E.

Thus, Sourav's chances hinge not only on his last league match with Patrick Einsle of Germany on Wednesday but also the results of other matches in his group.

Alex Davies currently tops the group with five wins from six matches, followed by Li Yinxi of China, who has won four of his five outings.

Tomorrow, Pankaj faces Nisar Ahmed Saif of Qatar and Aditya meets David Meer-Bailey of New Zealand. Sourav has a day off.

Title-holder Ding Junhui of China, meanwhile, shrugged off his shock defeat of yesterday to trounce Michael Wilson of New Zealand 4-0 with breaks of 70, 83 and 77 for his fifth win in six matches in Group A.

Century breaks continued to be made as Jamie Jones of Wales (109), Albert Kenny (106) and Jamie OFNeill (128)  cracked the three-figure mark. Thus far, the tournament has recorded 16 centuries.