The Aberdonian finished second to England’s Gabriella Cowley in the opening Rose Ladies Series event of the season at West Lancs, where Heather MacRae also made her presence felt on the leaderboard.
Thomson, who is waiting for the new Ladies European Tour campaign to get underway, followed an opening bogey with a brilliant burst of four straight birdies.
She turned in 34 after dropping a shot at the ninth before bogeys at the 13th and 16th coming home saw her sign for a level-par 72 and a share of second spot with Gemma Clews.
The pair were pipped for top spot by Cowley, who mixed five birdies with four bogeys in a roller coaster round at the Merseyside venue.
“A second place to start the ladies’ season is great,” said Thomson. “I hit the ball great today on a tough golf course and with the weather being so cold.”
Set up by Justin Rose and his wife Kate to provide playing opportunities for British-based professionals last year during the Covid-19 pandemic, this season’s schedule includes a visit to Scotscraig in August.
“We are so grateful that we have the Rose Ladies Series to play and are very thankful to the sponsors for backing women's golf,” added Thomson.
She played in the Royal Dornoch Masters on the Tartan Pro Tour earlier in the week, having also competed in events at both Montrose Links and Barassie Links over the past fortnight on the Scottish circuit set up by her manager, Paul Lawrie, last year.
“The warm up on the Tartan Pro Tour has helped me massively, playing with the guys has definitely improved my game,” admitted Thomson.
MacRae, the double WPGA champion, tied for fourth, having started with three straight bogeys but then covering the remaining stretch in two-under to card a gritty 73.
“I actually felt really nervous at the start,” said MacRae. “I was level on the 18th tee and knew I needed a birdie but, unfortunately, drove into a bunker I didn’t think I could reach and made a bogey.
“It was really nice to be back playing in a ladies’ event and I’m looking forward to Woburn next week.”
On the European Tour, Grant Forrest eagled the last to fare best among nine Scots in the opening round of the Tenerife Open with a three-under-par 68 at Golf Costa Adeje.
The effort left the Lothians man sitting in a tie for 38th as Dane Thorbjorn Olesen led the way on a low-scoring day with a nine-under 62.
The 2019 Ryder Cup player leads by a shot from a group that includes South African Garrick Higgo, fresh from his win last weekend in Gran Canaria, and American John Catlin, who had a chance of becoming just the second player to break 60 on the circuit before stuttering over the closing stretch.
“It’s the first real opportunity I’ve had at a tournament to shoot 59,” said Catlin, winner of the Austrian Open earlier in the month. “It was unfortunate to finish the way I did, but I’ll take the positives.”