Hawkins, who was beaten by John Higgins in the 2018 final, took control early on, winning the opening frame with a break of 105.
And although Lisowski drew level in the second frame, Hawkins would then go on to win six in a row.
Another century break in the fourth frame came in between three half-century breaks of 67, 76 and 88.
The afternoon ended with another Hawkins frame, as he led Lisowski 7-1 going into the tournament’s final session.
Lisowski, who was playing in his first Welsh Open final, showed great fight when the game restarted, putting together back-to-back century breaks to remind his opponent there was still work to do.
The 34-year-old then came out on top of a 40-minute frame which swung both ways to reduce Hawkins’ lead to 7-4.
But Lisowski’s momentum was ended in the following frame, as a long safety shot from Hawkins resulted in a red ball finding the bottom left pocket of the table.
And Hawkins made the most of the opportunity, putting together a break of 68 to put him on the cusp of victory.
Lisowski managed to win one more frame, with a break of 53, before Hawkins clinched the Welsh Open title in the 14th frame of the final.
“I was very poor despite trying my best,” said Lisowski.
“Barry was by far the better player today and he deserves his win.
“He’s been great to me my whole career, even when I was very young. He’s always given me the time of day so I’m very happy for him.”