The black, green and gold were snuffed out by Bath at Franklin's Gardens, losing 18-3 after second-half tries from Tom de Glanville and Ruaridh McConnochie.
Saints just could not force their way over the line as Bath revelled in the power game, forcing error after error from the hosts.
It was a fifth defeat in as many Gallagher Premiership home matches for Boyd's side in 2020.
And it means they remain outside of the top four, sitting sixth in the standings, while Bath are now in the play-off positions.
Boyd said: "I just said to the boys in the shed that we tried really hard so it's not a lack of trying but at the end of the day, you don't win games by trying, you win games by scoring more points than the other team.
"We're conceding too many too easily and not scoring enough ourselves so we need to rectify both ends of the field.
"There are fundamental mistakes, inaccuracies, poor executions and when the pressure comes on at the moment, we're just not able to get our game going, either defensively or offensively.
"When the space gets really tight like that, it's pretty hard for that X factor to come out.
"You've got to have a process and it's clearly not working often enough.
"We're probably forcing the ball a little bit too much and we have to go back to the drawing board.
"We've dug a hole for ourselves and it will be interesting to see how this young group responds to that."