Boyd took a fine diagonal pass from strike partner Jay Simpson in his stride within a minute of the second half and although under pressure from Huddersfield defender Peter Clarke, unleashed a drive into the top corner from the edge of the penalty area.
It was Boyd's fourth goal in six games for Hull since he arrived on loan from Peterborough last month and capped a memorable seven days for the 27-year-old, who made his Scotland debut against Serbia earlier in the week.
"That was the one bit of quality,'' Bruce said. "It was a great pass from Jay and it was a great finish from Boydy. He's had a wonderful start.''
Bruce, chasing a third promotion to the Barclays Premier League after successes with former club Birmingham in 2002 and 2007, added: "We've a huge game against Watford now on Tuesday. If we can go and get a result there, it's another game gone and you just want to protect that lead, that's the aim - can we protect it with seven games to go?
"It's a good position to be in, but there's still seven games to go and we know how quickly it can change. Who would have thought Leicester for example, would have won one of their last 10 and Palace I don't think have won in four or five, the way the Championship is, nothing surprises me.
"But if we can win (on Tuesday), it will be a huge result for us.''
Huddersfield manager Mark Robins felt his side had made big strides when they won at West Yorkshire rivals Leeds before the international break, but a sixth home league defeat has left them two points above the relegation zone.
"We weren't good enough,'' he said. "I don't think it was a great game by any stretch of the imagination. We restricted them to very little, but it's a difficult formation to play against, how they play it and with the quality of players they've got, they're obviously up there for a reason.''
Robins acknowledged Boyd's fine winner, but felt Town striker James Vaughan had been fouled in the build-up. "There was a real push in his back, but we can't blame incidents like that, we've got to come out and be better that this,'' he added.