After being gifted a free-kick in the penalty area at 1-1 when Swansea keeper Carl Rushworth got punished for scooping up a 77th-minute back pass from Harry Darling, substitute Silvera smashed home a shot from a short pass just a few yards from goal.
The strike, Silvera's second league goal and fourth in all matches this season, earned Boro a victory which manager Michael Carrick hopes will help spearhead their push to reach the Premier League.
And it prompted the former England and Manchester United midfielder to suggest it was down to "smart" work from Boro's two youngsters, Morgan Rogers and Silvera.
"It's a strange one. I've not seen it for a long time," said Carrick, who watched Rogers tap the ball fractionally to his right in the box with Silvera latching on to it with a thunderous strike past Rushworth at his near post.
He said it reminded him of his United days, when then teammate Cristiano Ronaldo once scored in similar circumstances at Old Trafford.
"They literally line everyone up on the line, so it's not a given - there's no easy way to find a way through (but) Sammy managed to find a gap," Carrick said.
"It was quite interesting to see what the lads came up with because it's not something you see often and therefore we haven't planned for it.
"But the boys, two of the younger boys as well, have been smart enough and bright enough.
"They stepped up and said, 'This is my moment, I know what I'm going to do', and that pleases me even more. It made the difference."
Silvera, the 23-year-old Central Coast Mariners' championship-winning star who made his debut for Australia in September in the draw with Mexico, has impressed at the Riverside Stadium since his move from the A-League to England in July.
His rise has come while Boro's star Socceroo Riley McGree has been sidelined for more than a month with a foot injury.
Carrick reported that McGree should be back in action soon, with the northeast club, currently 13th and five points off the crucial top six, still hoping to surpass last season when they were knocked out in the playoff semi-finals by Coventry.
Elsewhere in the Championship, Ipswich, with Socceroos Massimo Luongo and Cameron Burgess in their ranks, earned a 2-2 draw in the East Anglia derby at home to Norwich, a point that leaves them behind Leicester on goal difference at the top of the table.
- with PA
