It was all pretty straightforward for the three-time world champ as he played some good stuff and Lisowski struggled on his first appearance in a Masters semi.
Breaks of 52, 74 and 68 helped Williams along the way to the victory which he classes as one of his best for years.
The Welshman lost in the semis last year in a deciding frame to Neil Robertson, despite the Australian needing two snookers in that final frame, so Williams is thrilled to bounce back 12 months on.
‘It’s got to be up there. Last year I had my foot in the final then had three feet back out,’ he told the BBC.
‘To come back 12 months after throwing that match away and now be in the final, it’s got to be one of my best wins for a long time because I don’t get to finals as often as I used to and it gets more difficult the older you get.
‘I’d never had thought it years ago, but here I am.’
Williams won the Masters in 1998 and 2003, losing in the final in ’02, so it has been a full 20 years since having a crack at the showpiece and the first time he will at Alexandra Palace.
‘It’s been a long time,’ he said. ‘I played ok today, Jack struggled a bit, maybe a bit of pressure.’
He is aiming to win his first Triple Crown title since his memorable World Championship triumph in 2018, which saw him honour a bet by doing the press conference naked straight after the victory.
After turning down the suggestion to repeat that on Sunday, he said: ‘Although you give me the £250,000, I’ll probably just run around there naked.’
Lisowski was downbeat but classy in defeat, feeling he didn’t get much run of the ball, but Williams was the better player on the day in north London.
‘I thought Mark played some great stuff today and early on whenever he was missing it felt it was landing awkward for me, I definitely didn’t have any nudges today.
‘But he played great today, much better than me, he still looks really, really good.
‘I got some amazing support today but in the end wasn’t meant to be, I couldn’t win a frame, so back next year.
‘I couldn’t get anything going today, had no feel, he shut me out. These top players make it very, very tough.
‘I’ll watch the game back, dust myself off and I’ve got another tournament in two days, so back on the horse.’
Williams will meet either Judd Trump or Stuart Bingham in the final on Sunday.
MORE : Judd Trump enjoying criticism as Stephen Hendry comments spur him on at The Masters
MORE : Jack Lisowski backs himself to win ‘many’ titles ahead of Mark Williams Masters clash
For more stories like this, check our sport page.
Follow Metro Sport for the latest news on
Facebook, Twitter and Instagram.
Share your story or advertise with us: Whatsapp: +2347068606071 Email: info@newspotng.com