That was Melrose’s second win of the campaign and it leaves them in sixth place in the standings, on ten points from four fixtures, one place and one point better off than the Souters, beaten 33-12 at home to table-toppers Ayr on Saturday.
Drafted-in Edinburgh academy openside-flanker Jerry Blyth-Lafferty got a hat-trick for the Borderers in East Lothian and left-winger Corey Goldsbrough was only one behind him, with outside-centre Declan Mulcahy and replacement Douglas Crawford also touching down and full-back Keiran Clark kicking five conversions and two penalties.
Loosehead prop Craig Owenson scored their hosts’ only try, with fly-half Danny Owenson converting it and also kicking two penalties.
Blyth-Lafferty was one of two Edinburgh academy players and under-20 Scottish internationals in co-head coaches Scott Wight and Ian Chisholm’s starting XV, along with hooker Harri Morris.
Morris, 22, was delighted to have helped his old club pick up five points on the road, telling Borders Rugby TV afterwards: “The game went really well.
"It was pretty tough. In the first half, we had to stick in, but we did, and by the time the second half came round, we were able to get on top and run away with it.
“I was really chuffed with the boys and how they played and the way they stuck in. It was a good result.”
Head coach Gordon Henderson’s Souters’ trip to the Greenyards this weekend, with kick-off at 3pm, is their second derby of the season following a 22-12 victory at Kelso the weekend before last.
They go into it on the back of a loss to league leaders Ayr, keeping up their 100% start to the season, but they’ve learnt lessons from that defeat on Saturday that will stand them in good stead for the rest of their campaign, according to try-scorer Callum Anderson.
The full-back touched down both of Selkirk’s tries at home at Philiphaugh to the South Ayrshire side, with scrum-half Hugo Alderson converting one of them, but it wasn’t enough to stop head coach Grant Anderson’s visitors making it four bonus-point wins out of four, like second-placed Heriot’s.
Hooker James Malcolm at the double, drafted-in Glasgow Warriors left-winger Amena Caqusau, inside-centre Jamie Bova and replacement scrum-half Ben Frame scored Ayr’s tries, with fly-half Richie Simpson adding four conversions, as they fought back from being 7-5 down at half-time.
“You know what they say, that you either win or you learn, and it was definitely a massive learning experience for us,” said Anderson.
“I think we showed the rest of the league that we can compete with these teams. It’s just errors either side of the ball that lets others teams back into games.
“It was a good 40-minute performance from us but we didn’t take it into that second half.”
A solid defensive display was to thank for the Souters’ half-time lead, said Anderson, but unfortunately they weren’t able to keep it up for the full 80 minutes.
“Last week, we’d defended well against Kelso but it had to go up another level today,” he said.
“There were a few key turnovers from the back-row lads, which was really good, and to keep a team like that to five points at half-time, I was chuffed to bits with that.
“It was a really good learning experience for the team and we’ll be better for that game.”

1. Selkirk v Ayr
Full-back Callum Anderson en route to scoring his second try during Selkirk’s 33-12 loss at home to Ayr at Philiphaugh on Saturday in rugby’s Arnold Clark Premiership (Photo: Grant Kinghorn) Photo: Grant Kinghorn

2. Selkirk v Ayr
Glasgow Warriors left-winger Amena Caqusau on the attack during Selkirk’s 33-12 loss at home to Ayr at Philiphaugh on Saturday in rugby’s Arnold Clark Premiership (Photo: Grant Kinghorn) Photo: Grant Kinghorn

3. Musselburgh v Melrose
Scrum-half Bruce Colvine in possession during Melrose’s 51-13 win away to Musselburgh on Saturday in rugby’s Arnold Clark Premiership (Photo: Andy McLean) Photo: Andy McLean

4. Musselburgh v Melrose
Melrose getting a tackle in during their 51-13 win away to Musselburgh on Saturday in rugby’s Arnold Clark Premiership (Photo: Andy McLean) Photo: Andy McLean