Crisis-hit Manchester City slumped to an unthinkable ninth defeat in 12 matches at Aston Villa on Saturday as Arsenal dismantled Crystal Palace 5-1 to reignite their Premier League title charge.City boss Pep Guardiola -- in the worst spell of his managerial career -- made multiple changes following last week's painful derby defeat to Manchester United but it was to no avail as his injury-hit side lost 2-1.