Crespo sacked by Al Ain just months after AFC Champions League glory
The former Argentina striker's exit came a day after a 5-1 hammering by Cristiano Ronaldo's Al Nassr in Asia's top club competition, which left the defending champions bottom of the standings halfway through the group phase.
Recent results were "not up to expectations", a club statement said Wednesday, adding they would appoint a replacement within hours.
The 49-year-old Crespo took over in November last year and in May led Al Ain to victory over Japan's Yokohama F. Marinos in the two-legged final of the Champions League.
But the former Chelsea and Inter Milan star's side have been on a poor run of form since late September, the final straw being Tuesday's heavy away defeat to the Saudi side.
Ronaldo scored once in the rout.
Al Ain are languishing at the foot of the 12-team West zone standings in the AFC Champions League, now called the Champions League Elite, with one point from four games.
They have also had a poor start to their UAE Pro League campaign and are eighth in the 14-team table. Al Ain have eight points from five matches and are 10 points adrift of leaders Shabab Al Ahli.
