A first-ever Newcastle United brace from Hannah Greenwood - one goal coming in each half - was what United required to steer past a stubborn Boro defence
United put in a professional display over the 90 minutes, controlling the tempo of the game as well as creating the majority of the chances in the game.
It was the home side who dominated the opening exchanges, but they were left off the hook when Jess Mett intercepted a short back-pass in the box, but her effort rolled across the line and away to safety.
United slowly eased themselves into the game and after a smart save from Claudia Moan in the 20th minute, Newcastle sprung a great counter-attack. Amy Andrews flicked the ball over the Boro defence for Jasmine McQuade, but she could only fire straight at the onrushing Laura Wareham.
There was very little action in the first half, although Becky Langley's side continued to look for the opener and were camped inside Boro's half, but the visitors remained resolute.
However, Newcastle's pressure paid off just before the half-time whistle when Katie Barker cut inside from the left and her fizzing effort was too hot to handle for Wareham, allowing Greenwood to slot home from close range calmly.
The opening goal appeared to spur on United as they almost doubled their lead in stoppage time as Beth Lumsden cushioned a free header into the path of McQuade, who was thwarted by some sublime last-ditch defending from Grace Boyes.
It was the same story at the beginning of the second half, with Barker being played in behind and cutting inside once again. However, this time, Wareham did enough to tip her low effort around the post.
The away side were wheeling away in celebration eight minutes after the restart following Millie Bell's smart volley, but Boro's number 17 had strayed offside.
Both teams came out firing and looking to take control with Lumsden firing an effort off the crossbar just two minutes later after a mazy run forward from Demi Stokes.
Greenwood, who moved into centre-back for the second half, manoeuvred some space in the box to get on the end of Lumsden's cross, but United's number 15 could only direct her effort over the crossbar.
With just a one-goal advantage heading into the final ten minutes, United looked to make use of a set piece when Georgia Gibson's smart through ball fell to McQuade, but she couldn't navigate her effort goalwards.
However, that missed chance was quickly forgotten about when Middlesbrough failed to clear a Newcastle corner, with the ball eventually falling to Greenwood in the area, and she made no mistake with a thunderbolt half-volley into the bottom corner.
With just four minutes to play, Shania Hayles pounded on a loose Middlesbrough pass and played in Andrews, who drove into the box and repaid the favour by teeing up the Jamaican international - but she could only strike over from two yards out.
Newcastle United Women: Claudia Moan, Lia Cataldo (Lois Joel 45), Deanna Cooper (Georgia Gibson 45), Amber-Keegan Stobbs, Demi Stokes (Ella Baker 88), Hannah Greenwood, Emma Kelly, Jasmine McQuade, Katie Barker (Shania Hayles 62), Amy Andrews, Beth Lumsden (Kacie Elson 75)
Subs not used: Grace Donnelly, Hannah Hawkins, Liv Watt, Isabella Sibley