In the battle for the Jack Allan Cup, Blyth jumped ahead of the overnight leader, Stirling’s Oliver Bailey, thanks to an adventurous five-under-par 67 in the second round on the New Course.
His card featured an eagle at the par-5 third plus five birdies, including three in a row from the 13th, with some of that good work being undone by a double-bogey and two bogeys.
However, the joint best round of the tournament so far earned Blyth a three-shot lead going into the final two circuits as the men’s event switches to the Old Course.
After a second successive 72, Bailey sits in second place, a shot ahead of two other Stirling players, Alasdair McDougall, who recovered from a 6 at the first to match Blyth’s 67, and Michael Lawrie (72).
Brown, winner of the West of Scotland Trophy at Western Gailes earlier in the month, now has the Smith-Murray Cup in her sights after swapping places at the top of the leaderboard with team-mate Chloe Goadby.
As Goadby could only muster one birdie in signing for a 75, Brown picked up shots at the sixth, ninth and 12th in a stiff morning breeze as she carded a 73 for a four-over total, one ahead of Goadby.
Also in that title battle, which resumes on the New Course before concluding on the Old Course, is Lorna McClymont (SRUC) after she stormed into contention on the back of a 70.
*** Rory Franssen from Inverness has the leader in his sights heading into the final round of the Hootie at Bulls Bay Intercollegiate in South Carolina.
Missouri’s Franssen sits joint-second, just two shots behind Charlie Hiller (Kansas), after opening with scores of 67-69 at Awendaw.
Franssen is on eight-under, having has made 13 birdies so far in an event hosted by Hootie and The Blowfish Foundation.
His fellow Scot and Missouri team-mate, Jamie Stewart, is also in the top 10, sitting joint-seventh on four-under after rounds of 68-72.
Gemma Dryburgh’s growing confidence on the LPGA saw her finish with a flourish in the Bank of Hope Founders Cup in Phoenix, Arizona.
Playing in her first event on the circuit this year, the Aberdonian stormed home in three-under 33 in the final round as she closed with a 70 - her third sub-par round of the week - to finish joint-69th on five-under.
Last year as a rookie, Dryburgh missed the cut in her first nine events before starting to find her feet late on, signing off the season with a top-25 finish in the Portland Classic.
She then regained her card with a gutsy performance in the Qualifying School at Pinehurst at the end of last year.
Solheim Cup captain Catriona Matthew missed the cut in the Phoenix event, which was won by Korea’s Jin Young Ko by a shot from American sisters Jessica and Nelly Korda, as well as Spaniard Carlota Ciganda.
Paul O’Hara and Paul Bradshaw joined forces to win the latest PGA Winter Fourball event at Craigielaw, carding a 61 to finish three shots clear of the field.
Cameron Marr and Chris Currie finished second, followed by four pairs on 67 - Cameron Donaldson/Shaun McAllister, Alasdair McDonald/Andrew McHardy, Michael Paterson/Alistair Kyle and Alan Reid/Graham Fox.