Resilient Albion twice came from behind to secure a 4-2 victory over Huddersfield Town and preserve their unbeaten record in the Sky Bet Championship.
Matt Phillips struck in the 19th minute to quickly cancel out Lewis O'Brien's opener, although it was the struggling visitors who led at the interval as Karlan Grant capitalised on a defensive error.
However, Slaven Bilić's side were the dominant force after the restart and saw Phillips clip the woodwork before Darnell Furlong headed home his maiden goal for the club to level matters in the 70th minute.
And it was left for Phillips to put the hosts ahead just four minutes later, courtesy of a second assist for impressive half-time substitute Grady Diangana, before Semi Ajayi added a late fourth to ensure Albion remain unbeaten after their opening eight league matches - for only the fourth time in the club's history.
The battling Baggies have now secured 15 of their 16 points so far from losing positions, showing belief and spirit aplenty, with a trip to QPR next up on Saturday lunchtime.
Albion showed one change from last weekend's draw at Fulham, Filip Krovinović recalled in place of Diangana.
The hosts came close to taking an 11th-minute lead, Charlie Austin seeing his shot deflected narrowly wide after a sumptuous cross-field pass from Romaine Sawyers found Furlong out wide.
Yet it was Town who opened the scoring in the 16th-minute courtesy of O'Brien's fierce low, angled drive from the edge of the penalty area.
However, the deficit lasted just three minutes as Phillips side-footed home Austin's lay-off following excellent work from Furlong to put through the legs of Terence Kongolo down the right and surge into the penalty area.
The Baggies subsequently dominated possession as they looked to build but were punished for a defensive mistake 10 minutes before the break, Grant capitalising to put the visitors into a 2-1 lead at the interval.
Diangana replaced Krovinović for the second half and Albion almost restored parity immediately, Phillips firing over when well placed.
Tommy Elphick flicked captain Jake Livermore's strike on to the roof of the net before Phillips saw his teasing cross evade everyone and rebound off the far post.
Austin's header forced an impressive reflex save from Kamil Grabara, Livermore flashed a half-volley just wide and Phillips' long-range strike was tipped wide as the hosts pushed for a second-half leveller.
And it deservedly came in the 70th minute as Furlong rose highest to head home Dianagana's left-wing cross off a post.
Head Coach Bilić turned to Kenneth Zohore off the bench as the Baggies continued to press in search of all three points.
And the winner came courtesy of great work down the left from Diangana, who skipped into the penalty area and squared for Phillips to slot home his second of the afternoon and send the home crowd into raptures.
Ajayi then got in on the act to add a late headed fourth from Matheus Pereira's corner and ensure Albion secured back-to-back home wins.
Albion: Johnstone, Furlong, Ajayi, Bartley, Ferguson, Livermore (c), Sawyers, Phillips (Robson-Kanu 82), Krovinović (Diangana 46), Pereira, Austin (Zohore 72).
Subs: Bond, O'Shea, Brunt, Edwards.