Jordan Brown has progressed to the last 16 of the Gibraltar Open after a 4-0 win over England's Louis Heathcote, but Aaron Hill saw his tournament come to an end after a 4-1 loss to Ding Junhui.
Earlier Heathcote came from one behind with two to play to defeat Dubliner Ken Doherty, but he was no match for Brown.
The Antrim man will now face Welshman Jamie Jones on Friday after the world number 38 defeated Anda Zhang 4-2.
Hill, meanwhile, lost the first three frames to Ding and while he won the fourth, the 2016 World Championship finalist ended his run in the fifth frame.
Fergal O'Brien, Mark Allen, Gerard Greene and Leo Fernandez are all in action tomorrow.
The event at the Europa Point Sports Complex is the 14th ranking event of the season and will be played off over three days, with the final on Saturday.
Neil Robertson saw off three opponents in one day as he reached the last 16.
The Australian, the reigning Masters champion who has claimed ranking titles at the English Open and Players Championship this season, started his campaign with a 4-2 win over Liang Wenbo.
Robertson then defeated England's Oliver Lines by the same scoreline before brushing aside Jamaica’s Rory McLeod 4-1.
Kyren Wilson, the beaten finalist in 2020, and Ding Junhui were among the others to join Robertson in the fourth round in a competition that has been hit with a handful of unforeseen withdrawals.
World Snooker explained in a statement on its website: "Unfortunately due to bad weather in Gibraltar, certain flights from the UK have been diverted to Malaga.
"Players travelling on non-British passports and without a Schengen Visa do not meet the Spanish visa entry requirements and therefore have had to fly back to the UK and some will not able to compete.
"Their opponents at the tournament will receive a walkover into the second round and these will be confirmed as and when we know that the player is unable to make their match."
