But he didn't get carried away with the win, saying it only gave his side a valuable preliminary final at home and no more.
The Dockers were led by Michael Barlow's 32 disposals and three goals while Nathan Fyfe, Stephen Hill, Ryan Crowley and David Mundy gave him great support in the midfield and overcame Lyon's early concerns.
"Their clearance work was far superior to ours but then the midfielders and the rucks got to work and started to halve it in there and gradually worked away to get some ascendancy and give our forwards some opportunity," Lyon said.
Giant ruckman Aaron Sandilands was at his most dangerous when pushed forward and had a huge influence on the game in the third quarter, kicking a goal and created two more from stoppages.
Lyon said he thought the team could cover for Sandilands on the spread and considered it his best game for the season.
Fremantle youngsters Lee Spurr and Cam Sutcliffe also stood up under enormous pressure and were important in curtailing the impact of Geelong's small fleet of running players, as the Cats were restricted to just nine goals.
It was the Cats' lowest goal tally since round nine, 2008 when Collingwood kept them to just seven goals. Saturday's win also marked the third time since 2010 that a Ross Lyon-coached team has beaten the Cats in week one of the finals.
Lyon rubbished the notion that Fremantle had used the game's scheduling at Simonds Stadium as motivation. However, he did reinforce the club's overall philosophy that meant no one panicked when the decision was made.
"We want to be an 'anywhere, anytime' team and this is a significant challenge and they got it done today," Lyon said.
He said the impact of resting players in round 23 was hard to measure but he compared it to the perceived advantage of having a week's rest between winning a qualifying final and a preliminary final.
"You would not want to be doing it every week but after 22 home and away rounds, it clearly would help," Lyon said.
With the win behind him, Lyon's only concern now is who will be available in a fortnight. The match review panel will assess the game but his injury concerns are minimal.
Michael Johnson is likely to be available and Nick Suban suffered only a rolled ankle.
Clancee Pearce is out for the rest of the season while Garrick Ibbotson remains a week-to-week proposition, but he has not played since round 18.
