Andros was handed a first senior cap by Roy Hodgson and delivered in a match England had to win.
Starting on the right, his direct approach and willingness to take the opposition on - such a feature of his fine season at Spurs so far - was to the fore as England eventually ran out 4-1 winners to top qualifying Group H with one match remaining, against Poland at Wembley on Tuesday.
A product of our Academy, Andros carried the biggest threat in a goalless first half and it was another lung-busting run, this time fully 60 yards down the right flank, that led to England's opening goal three minutes into the second half.
His cross from the right byline eventually found Wayne Rooney who buried from close range.
An own goal doubled England's lead but Montenegro worked their way back into the game through Dejan Damjanovic with 71 minutes remaining.
Any fears of a comeback were quickly allayed however with the goal of the night from Andros, who picked the ball up 35 yards out, dribbled infield and then unleashed a drive with his weaker right foot that thudded home off the post.
Daniel Sturridge's late penalty capped a display that means if England beat Poland, they will qualify automatically for the World Cup Finals in Brazil next summer.
Kyle Walker also played the full 90 minutes but a yellow card - his second in qualifying - means he will now be suspended for the Poland match. Jermain Defoe was an unused substitute.
OUR GOALSCORING DEBUTANTS FOR ENGLAND
Andros is the seventh Spurs to mark his full England debut with a goal.
VJ Woodward v Ireland 1903
Bill Nicholson v Portugal 1951
Johnny Brooks v Wales 1956
Bobby Smith v Northern Ireland 1960
Glenn Hoddle v Bulgaria 1979
Steven Caulker v Sweden, 2012
Andros Townsend v Montenegro, 2013