On a day dominated by home player Ronan Mullarney as he set a new course record at the Rosses Point course with a nine-under 62, Walker and Muir carded matching five-under efforts to sit in a share of second spot.
Walker, one of six Scots in the initial Great Britain & Ireland squad for the Walker Cup at Royal Liverpool in September, made his score with a fast start, following an opening par with a birdie-eagle burst. The African Amateur champion added birdies at the fifth and seventh, followed his only bogey at the eighth with a birdie at the next before signing for nine straight pars on the back nine.
Muir, who won the Barassie club championship last year to add to three straight junior titles at the Ayrshire club, carded six birdies, including four in a back nine of 31. Liberton’s Kieran Cantley, who is also in the Walker Cup squad, made four birdies in the last eight holes as he shot a 68 to sit joint 12th, while Jim Johnston (Ayr Belleisle) and Jeff Wright (Forres) are also in the top 20 after matching 69s
Stephen Roger (Peebles), the leading Scot in the recent Lytham Trophy, had to settle for a 72, one better than Turnhouse’s Euan McIntosh, who is in the Walker Cup frame at the age of 50.
Making it seem as though he was playing a different course to anyone else, Mullarney made nine birdies, including five in a row from the 11th, as the Galway man set a blistering pace.
l Carly Booth, pictured, and Kylie Henry fared best of a nine-strong Scottish contingent in the first round of the inaugural La Reserva de Sotogrande Invitational. The pair fired one-under 71s to sit tied for 15th, five shots behind Charlotte Thompson after the English player set the pace with an effort that contained an eagle and five birdies. Kelsey Macdonald opened with a 72, but it was a struggle for Catriona Matthew as she opened with 76, as well as Michele Thomson (77), Vikki Laing (80), Jane Turner (81), Rachael Taylor (82) and Laura Murray (83).
l A second-round 75 left 2016 winner Robert Arnott with an uphill battle in the final round in his bid to reclaim the Senior PGA Professional Championship at Foxhills in Surrey.
On one over par after 36 holes, the Bishopbriggs Golf Range man sits eight shots off the lead after England’s Neil Cheetham backed up an opening 68 with a 70 to sit one ahead of compatriot Darren Prosser.