Two-time champion Mark Williams warned the rest of the Masters field that he will take some stopping, having defeated world number one Mark Selby in the first round.
Left-hander Williams edged a final-frame decider to beat Selby 6-5, with the Welshman having seemingly re-found his form in recent times, claiming a first ranking title in six years at the Northern Ireland Open in November.
I'm playing a hell of a lot better than I've done for many years.Mark Williams
And the 2000 and 2003 world champion was clearly delighted to have secured victory over the best player in the game.
He told World Snooker: "They don't come any tougher than the world number one.
"I'm over the moon. I'm playing a hell of a lot better than I've done for many years and if I can keep playing like that, then someone's going to have to play well (to beat me).
"I honestly don't care who I play next, I'm in the quarters now and if I'm still here at the weekend, then great."
Nortehr Irishman Mark Allen also claimed a place in the last eight as he saw off Luca Brecel 6-3, with the Northern Irishman feeling that he was well deserving of his victory over the Belgian debutant.
He added: "I felt I was the better player for most of the match.
"I wanted to put Luca under pressure at the start because it was his debut here. As the match went on I let myself relax a bit and scored well."
Allen can now be backed at 11/4 to win the Masters for the first time in his career, with Williams priced at 1212/1 and John Higgins 6/4.
View all Snooker betting