Soutar advanced from his opening game on Sunday with a 3-2 win over Diogo Portela.
The bookies made the local, who is a firefighter by trade, heavy odds-on favourite to beat Brazilian Portela.
But the game proved far from a formality, with scoring toing and froing in front of a packed Alexandra Palace crowd.
Soutar says he understood why he was favourite for the match, but added he always knew he’d be in for a tough time regardless.
“I get where people were coming from but I saw the bookies odds and was like ‘oh man’,” he said.
"That puts more pressure on you as a debutant.
"He’s been here loads of times before, it was a proper tussle and I’m just glad to come out the other side of it.”
The Alexandra Palace crowd has proved itself to be particularly tough on the Scottish players this year.
They’ve been subjected to certain chants against them and Soutar admits he found it tough originally to relax in front of the capacity audience.
"I was really, really nervous and I hold my hands up to that,” said the Red Lichties fan.
“Hopefully that’s out of the way now and I can be better for the next game.
"When I was out on the stage in the morning when there was nobody there I felt comfortable.
"I had a look about and thought, ‘it’s not as bad as you think’.
"But when there’s a crowd in there and they’re all English, apart from a handful of Scots, it was so difficult to switch off an concentrate on the darts.”
Soutar’s victory set him up for a final 64 tie against Austrian Mensur Suljović.
Suljović is one of the most high profile players on tour and will be a tough opponent.
But, with his opening game out of the way, Soutar believes he has plenty in the locker to advance beyond Christmas in the worlds.
"I’ve played in loads of darts tournaments and loads of games, you can play on the floor, you can play on the stage, but this is ‘Ally Pally’ and the World Championships, it’s the biggest thing I can play in,” he added.
"It’s also rankings, it’s my tour card and, moving forward against Mensur on Thursday, I think I can beat him but I’ve never played him before.
"If I turn up and play my UK Open stage game then I can beat him.
"I know there’s more to come.
"I love darts, I watch the interviews with other players, I watch what everyone is doing on the tour, I look at stats, I look at rankings.
"I’m aware of what he’s been doing and when he’s not been at the pro-tour.
"It’s pretty obvious he wasn’t at the pro-tours and his form was going to struggle.”
Soutar’s weekend match came just a few hours after fellow Scot Willie Borland lit up the tournament with a stunning nine-dart finish to advance from his opener.
Footage from his achievement was spread across social media and Soutar was as impressed as the rest of us.
"How can it not inspire you?” he added.