Ewan MacDougall’s men had got off to the perfect start after just three minutes.
Andy Mackay’s clean line-out take on the Greens’ 10-meter line allowed Ross Nixon to cut back towards his pack of forwards.
Henry Bithray was quickly up in support to release wing Josh Welsh, who burst up the touchline before stepping inside Kirk Ford to score the first try of the afternoon.
The home team was unable to make further headway, however, as Hawick’s big forwards began to up the ante.
On the half-hour mark, Bruce McNeil touched down for the visitors from a five-metre scrum, with Ally Weir adding the conversion.
Soon afterwards, full-back Kirk Ford crossed for Hawick’s second try after an overlap had been created wide on the right, giving the Mansfield men a 12-7 half time lead.
With the wind at their backs after the break, Selkirk soon cut the deficit. Aaron McColm’s clever inside break saw the scrum-half weave his way deep into Hawick territory, with Peter Forrest eventually forcing his way over the line for a try, following a series of forward breenges.
Hawick stretched their lead to 15-10 thanks to a Weir penalty, before referee Jonny Perriam awarded a penalty try to the visitors as a scrum collapsed on the Selkirk line.
Just before full time, Selkirk managed to pick up a losing bonus point, thanks to Aaron McColm’s well-taken try in the right-hand corner, but Hawick weren’t to be denied and kept their composure up to the final whistle.
Selkirk head coach Scott Wight couldn’t disguise his disappointment after the match.
“We started the game at a great tempo, went 5-0 up from a great try and, for the rest of the first quarter, controlled the way the game was going,” he said.
“Hawick came into the game towards half time, and then, after the break, we just didn’t play well enough, didn’t look after ball and didn’t use the wind behind us – something we’d spoken about at half time.
“It was hugely disappointing, so the only consolation is that we did manage to come away with a bonus point.
“Hawick played to their strengths, held on to the ball really well and got a penalty try out of us as well.
It was tough and physical out there but I thought we actually defended pretty well, but it was actually our attack that let us down.
“I still think we’re in a good place as a club.
“We had no serious injuries, so we’ll go back to the drawing board and focus on getting things right for our match this weekend at home.”