Pic: Top147.com
The Rocket lost the first three tight frames - two of them on the black - and could have gone 4-0 down if Campbell hadn't missed the pink off the last red after getting the three snookers he needed in frame four. O'Sullivan recovered to lead 4-3 only for the gritty Scot to level. Campbell had a chance in the decider and made 41 before playing safe. O'Sullivan crashed in a long red, added a superb black and went on to clear with 77 for victory.
The three-time World Champion will now play Mark Williams in what will surely be a marquee game for the tournament.
O'Sullivan said after the match: "All credit to Marcus, he's had a great season and been a top player for a few years. We had a good match there, he was up 3-0 so a lot of credit goes to Marcus but I was pleased to get through in the end.
"I tried hard, it was a difficult start, I got no luck. Everything went against me, I just didn't feel like I was getting into the game. I lost a couple of black ball games, so it was hard really. Then after the break the balls went a bit better for me.
"I tried to go for a 147, but I don't try to fulfil anybody's needs, I just go out there to try and do the best job I can do. If they're happy with that then great, but if not then there's not a lot I can do about that. All I can do is try my best on any given day, which I do. Sometimes you play brilliant matches and brilliant tournaments and some days you don't.
"My doctor has told me not to play. He's told me to take a long break so I'm probably playing against doctor's orders. It's hard if you keep missing tournaments. I just decided to take a risk and see how I feel when I came out here. Also the Chinese fans have been superb to me over the years so it's nice to come and see them and perform for them."
There was a shock on table two as 2005 World Champion Shaun Murphy was dumped out of the competition 5-2 by 18 year old wildcard Lu Ning. The young Chinese player looked to have thrown a 2-0 lead away when the World number five came back to 2-2 with a highest break of 62. But Lu made outstanding back-to-back breaks of 114 and 119, bringing the crowd to their feet and taking the lead 4-2. He had already knocked out Jamie Jones in the previous round and finished today with a break of 68 to progress to a match with Ali Carter.
Peter Ebdon, who loves the playing conditions in Beijing, got past Matthew Stevens 5-3 to set up a meeting with John Higgins in the second round. The 2002 World Champion recorded breaks of 72, 104 and 86 while Stevens managed 127 and 62.
After the match a tearful Ebdon attributed his recent return to form to the vegan diet he has dedicated himself to since his father passed away 18 months ago.
Ali Carter and Dominic Dale were never more than a frame apart as they played out a thriller, with 2010 Shanghai Masters champion Carter finally taking the match 5-4. Carter scored highly with breaks of 119, 95, 62, 58 and 51 while Dale hit a 63. Carter, who suffers from Crohn's Disease, reiterated his possible intention to retire from snooker on health grounds at the end of the season in his post-match press conference.
