Arsenal were beaten for the first time this season as William Saliba’s red card played a key role in their shock 2-0 Premier League defeat at Bournemouth on Saturday.Mikel Arteta’s side had started the campaign with a 10-match unbeaten run in all competitions, but that streak was shattered in controversial circumstances on the south coast.Arsenal defender Saliba was sent off after half an hour for a professional foul on Evanilson that was initially given as a booking before being upgraded to a red card after a VAR review.The Gunners finally cracked in the closing stages as Ryan Christie put Bournemouth ahead.Justin Kluivert’s penalty ensured Arsenal would lose for the first time since their Champions League quarter-final second leg defeat at Bayern Munich in April.It was a bitter blow for Arsenal, who would have gone top of the Premier League with a victory but now have to face title rivals Liverpool next weekend without the suspended Saliba.Third-placed Arsenal will be four points behind Liverpool by then if the leaders defeat Chelsea at Anfield on Sunday.Arsenal were well below their best in an unusually lethargic display, underlining the importance of injured forward Bukayo Saka, who was absent after coming off during England’s defeat against Greece last weekend.They will look to bounce back against Shakhtar Donetsk in the Champions League on Tuesday.A 1-1 draw at the Vitality Stadium in December 2019 was Arteta’s first game in charge of Arsenal.The Gunners have come a long way since then, transformed into perennial title contenders by the Spaniard.But losing to Bournemouth for only the second time in their history was a significant setback to their bid to win a first English title since 2004.– Arsenal malaise –Arsena