Mumbai City's Diego Forlan (centre) is shown a red card by the referee during the Indian Super League-3 first leg semi-final against Atletico de Kolkata at Rabindra Sarobar Stadium in Kolkata on Saturday. Mumbai City lost 2-3. Pic/Sportzpics

Kolkata: Mumbai City handed Atletico de Kolkata a major advantage after losing 2-3 in an enthralling first leg semi-final tie of the Indian Super League-3, which saw the visitors concede two-goal lead to taste defeat at Rabindra Sarobar Stadium, Kolkata on Saturday.