The wing-back, enjoying his first full summer with the Red Dragons after joining last year, featured in the opening 45 minutes as Sam Smith's first-half goal secured the win.
Thomason said the performance showed clear improvement in the squad's match sharpness compared to last week's goalless draw against Wisla Krakow, reflecting the benefits of their pre-season preparations.
“I definitely felt fitter and sharper. In that first game, you’re always trying to get a bit of rhythm back in your legs and you come off the back of a tough week in your first week and it’s about getting used to things after 8-9 weeks since last playing a competitive game,” he told club media.
“I felt much better. You could see today. Everyone looked a bit more at the races. Without the ball we were really well organised and a lot cleaner in possession.
“Pre-season ultimately is about building up match fitness and getting sharp, but it’s always great to have a benchmark against some of the best players in the country. I thought I did well personally, and we did collectively, and we had a really productive 45 minutes.”