Boro made further progress in the League Cup after beating higher-division West Brom in the wind and the rain at Stockton.
A Lauren Robson goal proved decisive as Boro turned in another terrific performance.
After their 3-0 win over York in midweek, Michael Mulhern made just one change to the starting 11, with Laura Wareham coming in for Ruby Cook in goal.
With seven available on the bench, Fran Ward and Maddie Myers also made their way into the squad.
Leanna Giles almost created the first chance of the game, playing a good ball through to Jess Mett on the break but the West Brom 'keeper raced out and collected before Mett could shoot.
In the early exchanges, an individual battle began to come to light as Ellen Turnbull and her opposite number fought for the ball. Turnbull won the early battle.
Robson's hold-up play created Boro a flurry of chances, playing the ball out wide for Abby Towers to deliver to the back post. Armani Maxwell made the best contact with it among a scramble of attempts on goal, but the West Brom 'keeper managed to get hold of the ball end the chance.
Minutes later, shouts for a Boro penalty were waved away by the referee as Turnbull looked to be tripped in the box.
Just inches separated Boro from going ahead when Jess Mett fired a volley across goal which had the 'keeper beaten but was just wide of the post.
With a good spell of pressure to build on, Boro hit the front through Robson as she was alert to a poor touch from a West Brom defender and fired into the roof of the net after driving down on goal.
An injury to Mett brought the game to a pause and the half to an end. The game later resumed after Mett was taken to hospital as a precaution with Faye Dale replacing her for the second half.
Wareham had her first major call to action in the second half, pulling off a great save to tip the ball around the post after a shot came her way from close range.
West Brom saw more of the ball in the second half but Boro remained resilient and dug deep to see off spells of visiting possesion.
Keira Skelton was forced off due to injury on 70 minutes, replaced by Grace Boyes as Boro looked to see out the last 20 minutes of the game.
Not long after, Sarah Burn was introduced, coming on for Millie Bell who had battled well in midfield all game.
With ten minutes to go Boro dug in and had to see out West Brom's attempts to throw the kitchen sink at the game to grab an equaliser.
A real spirited and united second half got Boro through the game and took the first-half goal all the way to the final whistle to get them through to the next round.
Middlesbrough: Wareham (C), Skelton (Boyes 70'), Packham, Towers, Turnbull, Mett (Dale 46'), Maxwell, Robson, Giles, Wilkinson, Bell (Burn 78')
Unused subs: Cook, Foster, Ward, Myers,
West Bromwich Albion: Miller, Brown, Reynolds, Green, Haughey, Rabjon, Watkins, Warner, May, Jhamat, Mahood
Subs: George, Andrews, Pullen, Oakley, Harris, Evans,