Perfection is hard to obtain, and so it proved for Melbourne City on Saturday at Fawkner.

Joe Montemurro's side ensured they finished the W-League regular season having won every game of their inaugural campaign, but were made to sweat by a persistent Sydney FC.

Melbourne City players celebrate Marianna Tabain's winner. Credit:Getty Images

It took Marianna Tabain's second goal of the afternoon - five minutes from time - to secure the three points for Montemurro's team, their twelfth win from as many starts.

Tabain had put City ahead in the 52nd minute, but Princess Ibini's 71st minute equaliser - the first goal City had conceded in more than two months - had placed the hosts' hopes of achieving the rare feat in danger. But Tabain's late chip over Sydney keeper Michelle Betos was enough to see City to victory.