China's reigning world champion Zhao Xintong opened up a slight lead over England's Liam Highfield on an emotional opening day of the tournament at the Crucible.Zhao is 5-4 up against Highfield, 92nd in the world rankings, with the match to be concluded on Saturday from 19:00 BST.On the other table, Northern Ireland's former world number one Mark Allen is 3-5 behind against China's Zhang Anda, with their second session to come on Sunday morning.Before play started a host of the sport's biggest names, including the BBC television team, paid tribute to former player and commentator John Virgo, who died in February aged 79, with a minute's applause.BBC presenter Hazel Irvine said John was "universally loved by everyone in this sport and beyond - he really was the voice of snooker".On Thursday there was a memorial service for Virgo in his home city at Sheffield Cathedral, a short walk from the Crucible."The cathedral was packed and we gave John a wonderful send-off as he was a very special man," 1985 world champion Dennis Taylor told BBC Radio 5 Live."I knew him for more than 50 years and he was a great all-round entertainer. There's a big gap here in the Crucible this year with John not being with us."Zhao became the first Chinese player to win the World Championship when he beat Mark Williams 18-12 in the 2025 final, and he has won four tournaments this season, including three of the past five ranking events.That form has taken him to fourth in the world rankings and he has been tipped by many players and pundits to win this competition.He won three of the opening four frames, including a break of 123 in frame four, but Highfield took advantage of mistakes to win three successive frames, including a break of 86 in the fifth.Highfield, 35, only returned to the World Snooker Tour last year after he suffered a broken wrist in an e-scooter accident in 2023, and had to win four qualifying matches to secure his Crucible spot.He had chances to take the final frame of the session but missed a yellow off the spot early on as Zhao nudged back in front.On table two, only eight of a scheduled nine frames could take place, with Zhang, 22nd in the world, two frames ahead as he searches for a first win at the Crucible after losing in the opening round on his five previous appearances.Allen, a Crucible semi-finalist in 2009 and 2023, made a 147 break at this venue last year during his loss to Chris Wakelin in the last 16.But Allen failed to register a single half-century break against Zhang, who made two centuries - 129 in frame two and 109 in frame five - as well as three breaks of at least 58.Three-time champion Mark Williams begins his campaign in Saturday's afternoon session when he plays Antoni Kowalski, the first Polish player to qualify for the Crucible.Xiao Guodong takes on Zhou Yuelong in an all-Chinese match, and in the evening session former runners-up Barry Hawkins and Matthew Stevens go head-to-head.Watch: World Championship - champion Zhao v Highfield; Allen v ZhangO'Sullivan chasing eighth Crucible title aged 50World Championship 2026: Matches, top seeds & BBC TV schedule