Just a second win in 16 attempts away at Newcastle is only half the job done for Albion, though, as they also require Swansea City to lose at home to Chelsea in the day's late kickoff.
With momentum on their side following their recent unbeaten streak, a previously down-and-out Albion side went with an unchanged starting lineup in the North-East.
Newcastle were unable to find the killer final ball for large parts of the opening 45 minutes, but it was the hosts who created the better chances heading into the interval.
A slightly trickier opening was then wasted by Mohamed Diame, who lifted the ball over the crossbar, though from the resulting corner Gayle headed goalwards and Foster produced a sublime save from point-blank range.
In an open start to the second period, Jay Rodriguez miscued his volley after being picked out by Phillips on the penalty spot in another warning for the hosts.
Rondon blasted wide from a good position and Chris Brunt was a little closer with his shot from range, with Albion - the worst team in the division for holding onto a lead - looking comfortable heading into the final 20 minutes.
Newcastle were fortunate not to be a man light for the closing stages after substitute Islam Slimani booted the leg of Craig Dawson, which will likely bring a retrospective ban and an end to his United loan spell.
There was to be no late drama at St James' Park, however, meaning that West Brom's eight-year stay in the top flight is prolonged by at least another couple of hours.
NEWCASTLE UNITED (4-4-1-1): Dubravka; Yedlin, Lascelles, Lejeune, Dummett (Murphy 58'); Ritchie, Shelvey, Diame, Kenedy; Perez (Joselu 78'); Gayle (Slimani 65')
WEST BROMWICH ALBION (4-4-1-1): Foster; Nyom, Dawson, Hegazi, Gibbs; Phillips, Livermore, Brunt, McClean (Evans 90'); Rodriguez (Krychowiak 77'); Rondon (Robson-Kanu 94')