West Brom ramped up the pressure on Arsene Wenger with a damaging 3-1 victory over Arsenal on Saturday.
As banners for and against Wenger were flown over The Hawthorns, Craig Dawson headed the Baggies in front on 12 minutes before Alexis Sanchez's thunderous drive hauled the Gunners level three minutes later.
Substitute Hal Robson-Kanu notched only his second goal for West Brom after the break before Dawson's second saw the hosts end a two-game losing streak in style.
A third successive defeat on the road leaves Arsenal in fifth, five points behind Liverpool in fourth, while Albion tighten their grip on eighth.
The latest top-flight outing provided the platform for disgruntled Arsenal fans to stage another protest against Wenger, as a plane towing 'No contract #WengerOut' flew over the ground ahead of kick-off, and his afternoon got worse on 12 minutes when Dawson rose highest to head Nacer Chadli's corner beyond Petr Cech.
A second banner - reading 'In Arsene We Trust #RespectAW' - then flew overhead and was shortly followed by Arsenal's equaliser, Granit Xhaka slipping Sanchez in behind the stationary Chadli and allowing the Chilean to rifle the ball past Ben Foster via the crossbar.
Saloman Rondon, looking to score his first Premier League goal since December 14, went close to breaking his duck on the half-hour mark, but pulled a shot wide.
Having both had their defences breached inside the opening quarter of an hour, both Foster and Cech were then called upon to preserve parity.
Foster showed great agility to thwart Aaron Ramsey's shot on the turn before Cech went one better, tipping Darren Fletcher's forceful drive behind, but that was to be Cech's last substantial involvement as an innocuous leg injury saw him replaced by David Ospina moments later.
Rondon nearly ensured the Colombian's first task was to pick the ball out of his own net, but his 50th-minute header flashed wide.
Injury forced Rondon off shortly after but his replacement, Robson-Kanu, had an immediate impact from the bench, the Wales international poking home his second Baggies goal after Ospina fumbled a cross after 55 minutes.
2 - Hal Robson-Kanu scored with his second touch of the game, just 75 seconds after coming off the bench. Impact.— OptaJoe (@OptaJoe) March 18, 2017
It took 10 minutes for Arsenal to conjure a response with Danny Welbeck, making only his second start of the season, heading Xhaka's corner onto the crossbar.
But having had a reprieve, the hosts nearly extended their lead a minute later as Ospina's hesitancy to come off his line saw Robson-Kanu go through on goal.
The Arsenal stopper made amends though, blocking Robson-Kanu's effort before Shkodran Mustafi cleared Chadli's follow-up off the line and Chris Brunt blazed over.
But Dawson wrapped up the victory when he got clear of Alex Oxlade-Chamberlain and Aaron Ramsey at another corner to head his second beyond Ospina.
With Arsenal managing just two shots on target throughout the duration of the game, the latest of which coming on 33 minutes, Wenger substituted Sanchez on 78 minutes, despite the Gunners needing two goals.
That only added to the discontent in the away end, as anti-Wenger banners began to surface in tandem with Arsenal's failed attempted revival.
West Brom: Foster (7), Dawson (9), McAuley (7), Evans (8), Nyom (8), Livermore (8), Fletcher (8), Brunt (7), Chadli (7), McClean (7), Rondon (6).
Subs used: Robson-Kanu (7), Yacob (4), Field (n/a).
Arsenal: Cech (5), Bellerin (6), Koscielny (5), Mustafi (6), Monreal (5), Ramsey (5), Xhaka (6), Walcott (5), Oxlade-Chamberlain (6), Sanchez (6), Welbeck (6).
Subs used: Ospina (4), Iwobi (4), Giroud (4).
Man of the match: Craig Dawson