Arsenal fans welcomed Shakhtar Donetsk to the Emirates Stadium for a Champions League showdown on Tuesday evening. Mikel Arteta will have been desperate to see his Arsenal side get back to winning ways after their unbeaten start to the season came to an end against Bournemouth on Saturday. The hosts dominated the opening period, but needed a stroke of fortune to go ahead as Gabriel Martinelli’s strike hit the upright before ricocheting off the goalkeeper and trickling over the line to be recorded as an own goal. The Gunners were far too sloppy after the break, and Leandro Trossard’s failure to…