Former world No. 1 Mark Selby thumped fellow Englishman Ricky Walden 5-2 in the second round of the World Snooker China Open in Beijing yesterday to regain top place in the rankings.

Compatriot Judd Trump was beaten by Jack Lisowski in the first round, which meant that if Selby reached the quarterfinals, he would be back as world No. 1 and the 30-year-old did the needful by jumping on to a 3-1 lead with a break of 91 in the first frame before the interval.

Walden made a game of it by taking one frame after the break but that was all he could manage.

"Obviously I'm happy (to be back at No. 1), but the main thing is to still be in and win this tournament and then lead it to the World Championships," said Selby, who will take on Mark Williams in the quarterfinals.

Welshman Williams fought back from 2-4 down to stun England's Ali Carter 5-4.

Lisowski made the quarterfinals of a ranking event for the first time in his career as he came through a thrilling 5-4 match against fellow Englishman Mark Davis.

Elsewhere, Shaun Murphy of England advanced with a 5-3 triumph over compatriot Rory McLeod while Australian Neil Robertson beat Mark Allen of Northern Ireland 5-1.