Judd Trump ended the hopes of schoolboy Jackson Page on his way to the quarter-finals of the Welsh Open while world number one Mark Selby suffered a shock defeat by 17-year-old Yan Bingtao.
Page, who is 15 and had been given a wildcard entry, could not follow his victories over Jason Weston and John Astley against the world number four.
Trump set himself up for a comfortable 4-0 win after opening with breaks of 61 and 96, before going on to beat Iranian Hossein Vafaei Ayouri in the evening session to reach the last eight.
Ayouri had earlier stunned Ali Carter in the round of 32 with runs of 136 and 123 in a 4-1 win but Trump never looked in any danger of going the same way in their evening showdown as three half-century breaks saw him progress.
Earlier on Thursday, there had been a shock in the round of 32 games when world champion Selby was beaten 4-1 by Bingtao, the Chinese player ranked 66 sealing an unexpected victory with a 99 break.
However, Bingtao's memorable 17th birthday would end with a 4-1 defeat in Thursday's evening session by Norway's Kurt Maflin, who opened up a 3-0 lead before the Chinese teenager produced a break of 136.
Barry Hawkins, winner of last week's World Grand Prix in Preston, recorded two century breaks as he beat Craig Steadman 4-0 to secure his quarter-final showdown against Trump.
There was disappointment for home player Lee Walker after he was defeated 4-0 by China's Zhou Yuelong, while Stuart Carrington saw off Brazilian Igor Figueiredo 4-1.
Thursday's later matches also saw Scott Donaldson reach the quarter-final by edging out Mark Davis 4-3.
Stuart Bingham coasted past Robbie Williams 4-0 and will play Carrington for a place in the last four, while Robert Milkins beat Mei Xi Wen 4-2.
Earlier on Thursday, Davis had scored the highest break of the tournament so far with 144 in the opening frame of his 4-2 win against Fergal O'Brien.
Northern Ireland's Mark Allen lost 4-2 against Xi Wen of China and Walker put out Scotland's 2006 world champion Graeme Dott 4-2.