Ronnie O'Sullivan navigated an intruder and John Higgins as he made the quarter-finals of the English Open in Barnsley.

The five-time world champion knocked old friend Higgins out 4-3 in a high-quality clash but it was an earlier encounter with an eager fan which was the story of the day.

Playing his third-round clash with Zhang Yong during the morning, the Chigwell star - a keen runner himself - saw a middle-aged woman evade Metrodome security and circle the table, telling the stunned potter she was "going for a jog".

Carrying an orange handbag and dressed in blue jeans and a grey top, the woman did not present an obvious security threat but regardless, O'Sullivan took it in good spirits.

He was on a break of 123 at the time and, as the woman jogged around him, he got down and fired in the pink to move on to 129.

Then, as the woman was ushered away, O'Sullivan offered her his cue and watched on as she made two poor attempts at sinking the black.

"I didn't know what to do at first and she just said, 'I'm just having a jog, I'm just going for a jog'," O'Sullivan told Eurosport.

"And I was like, 'Go on then, carry on then, there's your jog, have a shot as well while you're at it'.

"I thought she was going to pot it. I really wanted her to pot it.

"I thought when the (security) guys came out they were going to rugby tackle her, but I thought, 'If you do that, you might kill her'."

Having laughed his way through the incident, O'Sullivan returned to see off Higgins, saying: "When you play John you have to play well and if he plays to his best you're just a passenger."

There was a surprise as Shaun Murphy was dumped out 4-1 by Alexander Ursenbacher, the 21-year-old Swiss, while there were wins for the likes of Neil Robertson, Michael White, Yan Bingtao and Hossein Vafaei.

World champion Mark Selby went out in the third round, beaten 4-1 by Xiao Guodong.