The six-time world champion faced 40-year-old David Gilbert in the first round, and endured a woeful start as he fell 3-0 behind early on.
However, the world No.1 was able to regain his composure and draw on his vast experience to claw his way back into the game, before going on to win the tie 10-5.
At 3-0 down, O'Sullivan went on to win six successive frames and convincingly swing momentum back in his favour.
Gilbert then responded well at the start of the second session by taking another two frames early on, but once O'Sullivan refound his rhythm, the 46-year-old didn't look back, winning another four successive frames to secure victory.
Following his win, O'Sullivan was asked what inspired his comeback, and he suggested that his "gladiator" spirit helped him over the line.
"I am out there playing, enjoying it and just trying to compete. It is like Gladiator. Russell Crowe has a hole in his arm and knows he is going to die, but you just have to find a way. That is what winners and gladiators do.
"I probably wasn't born to play snooker, but I was born to do something with a ball. I just wish it would have been another sport where my temperament would have been suited to it. I find snooker challenging.
"To be the best at something it takes graft, time and effort. Sometimes you ask yourself, 'Why am I doing this?'
"I was never born a winner, but I had to have it drummed into me. A bit like Serena Williams and Tiger Woods, I had that type of father figure where I was told, 'You are going to be a success'.
"I wasn't that bothered, but I was toughened up mentally. I was mentored that way."
Now in the second round, O'Sullivan will either face Mark Allen or Scott Donaldson.
Should O'Sullivan go on to win a seventh World Championship title, he'll equal the all-time record currently held by Stephen Hendry.