* Arsenal crushed West Ham United 4-1 as Wenger goodbyes began
* Nacho Monreal put Arsenal in front at a 51st-minute corner
* Marko Arnautovic fired in the equaliser 13 minutes later
* Ramsey restored Arsenal’s lead with eight minutes remaining
* Alexandre Lacazette fired in two more goals in five minutes
* Arsenal visit Manchester United next, West Ham host Man City
April 22 (Reuters) - Arsenal scored three goals in the final eight minutes as manager Arsene Wenger marked his penultimate home Premier League match in charge with a crushing 4-1 win over West Ham United in a London derby at the Emirates on Saturday.
Defender Nacho Monreal put Arsenal ahead six minutes into the second half when he fired low past Joe Hart at a corner to bring the match to life after a dull first half.
Marko Arnautovic equalised 13 minutes later when substitute midfielder Manuel Lanzini fed him on the left and the striker shot past the diving David Ospina into the bottom far corner.
Aaron Ramsey put Arsenal ahead again in the 82nd when a mistake in the Hammers defence allowed his effort from the left edge of the box to sail into the far side of Hart’s net and Alexandre Lacazette added the third and fourth goals.
Hart had previously kept West Ham in the match with diving saves from Xhaka and Danny Wellbeck but Arsenal climbed within six points of fifth-placed Chelsea on 57 while West Ham remain in relegation trouble six points above the drop zone on 35. (Reporting by Rex Gowar; Editing by Clare Fallon)