Albion recorded back-to-back wins for the first time this season with a 3-0 triumph over Southampton on Monday evening.
First-half efforts from Matheus Pereira and Matty Phillips, as well as Callum Robinson’s well-taken strike, earned the Baggies an important three points at The Hawthorns.
And Sam Johnstone completed a fine performance with a magnificent penalty-save late on to deny James Ward-Prowse and ensure he kept Albion's sixth Premier League clean sheet this term.
The result means Sam Allardyce's side have notched eight goals in their last two games and adds momentum to their fight for survival ahead of seven final fixtures.
The gaffer opted to bring Callum Robinson into the starting XI following his fantastic display at Stamford Bridge last weekend.
And his team thought they had made the perfect start inside the first five minutes when Mbaye Diagne headed Darnell Furlong’s drive home, only to see the assistant referee’s flag immediately raised. A lengthy VAR check decided to controversially chalk the goal off, citing inconclusive camera angles as the reason why the original call stood.
The Baggies were dominating and could have opened the scoring a number of times, as Robinson poked wide and Conor Townsend had one well saved.
In what started to become an end-to-end clash, Southampton then went close through Danny Ings and then Stuart Armstrong, with the latter being kept out by a brilliant Johnstone stop.
But it was Albion who took control of the contest shortly after the 30 minute mark. Pereira won, and powerfully converted, a penalty to net his ninth of the season and put the hosts ahead.
179 seconds later things got even better - Diagne latched onto a misplaced pass down the left and sent a superb cross towards the far post, where Phillips was waiting to finish from a tight angle.
Southampton came out fighting in the second-half but couldn’t find the goal to get back in it. Kyle Walker-Peters saw two shots fly off-target before Albion No.1 Johnstone denied England team-mate Ward-Prowse.
This gave the Baggies the chance to wrap things up if they could find another - which they did 21 minutes from time. A fast break saw Robinson go one-on-one against Fraser Forster and the in-form attacker made no mistake.
Albion looked like they'd ended the scoring with Robinson's second in as many games, but Southampton had other ideas as they continued their push for a consolation.
The visitors broke fast in the closing stages of extra-time and after substitute Che Adams guided a shot inches wide of the bottom corner, Southampton got their reward.
The Baggies failed to clear danger in the box and Conor Townsend rashly took out a Saints attacker with a lunging challenge, leaving referee Simon Hooper with no choice but to award a late penalty.
Set-piece specialist Ward-Prowse confidently stepped up to the mark and hit a powerful penalty, but Johnstone guessed correctly to make a fantastic diving save to his right and preserve Albion's clean sheet and cap off another big three points.
Albion: Johnstone, Furlong, O’Shea, Bartley (Ajayi 85), Townsend; Yokuslu, Maitland-Niles; Phillips, Pereira, Robinson (Gallagher 72); Diagne (Robson-Kanu 76).
Substitutes: Button, Peltier, Gibbs, Livermore, Diangana, Grant.