The 'Rocket' was in ominous form early on, claiming the first two frames with successive breaks of 74 and 92.
Hawkins showed spirit to respond in his first Crucible final, restoring parity with two breaks above 80 to show the form that helped him reach this stage for the first time.
The world number 14 edged ahead at 3-2 but his advantage was short-lived as O'Sullivan rattled off three quick frames featuring two century breaks.
Hauls of 113 and 100 helped the four-time champion surpass Stephen Hendry's mark of 127 Crucible breaks totaling three figures.
Once again Hawkins fought back as the two players were locked at 7-7, but O'Sullivan used all his experience to build a late lead with more composed shot selection.
Breaks of 103 and 106 in the evening session mean that O'Sullivan takes a three-frame advantage into tomorrow's third session, with Hawkins still a live contender in the match.