Fans staged a massive protest in, out and over the Hawthorns against Arsene Wenger who saw his side lost 3 - 1 to West Brom.
Defender Craig Dawson netted a headed brace to pile further pressure on Arsene Wenger.
The lost was the Gunners fourth defeat in their past five Premier League outings which leaves them in fifth place, five adrift of Liverpool.
Dawson was left unmarked in the box to score the opener before Alexis Sanchez fired a 15th minute equaliser - his 22nd goal in all competitions this season - from a cross field pass from the impressive Granit Xhaka.
Petr Cech had to be taken off after suffering an injury after making a superb stop from Darren Fletcher's volley.
Albion substitute Hal Robson-Kanu, released by the Gunners as a schoolboy, restored the lead 10 minutes after half-time when he poked home a loose ball in the box.
A plane sporting a banner urging Wenger to stand down emerged at kick-off, although another trailing the slogan "In Arsene we trust" appeared overhead around the time Sanchez scored.
Liverpool are five points better off in fourth, while sixth-placed Manchester United can leapfrog them with victory at Middlesbrough on Sunday.