Saturday's game is key to the minor premiership.
Dropping their only points in the 1-1 home draw with City in round four, Waitakere have won their six games since scoring 26 goals and conceding just five and never more than one a game.
Following their 9-1 romp over Waikato FC six days earlier, the Waitakere fans were expecting more of the same against YoungHeart Manawatu at Fred Taylor Park on Saturday. They eventually emerged 4-0 victors but it was not as one-sided as the score might suggest.
Two Tim Myers headers from Chad Coombes corners in the space of three minutes gave United their 2-0 lead after 30 minutes but it was not until the same point in the second half that Roy Krishna stretched that margin.
Krishna, now a clear leader in the golden boot with 11, added his second five minutes into stoppage time.
In yesterday's game at Bluewater Stadium in which eight players were booked, Auckland City took the 58th minute lead when Pedro Cecilia stroked the ball into the corner of the Hawkes Bay goal.
The home side completed the scoring in the 70th minute when former All White Jarrod Smith powered a header past Tamati Williams.
Waikato FC bounced back from that drubbing to hold Team Wellington away for all but the last minute when Luke Rowe scored.
In yesterday's other game, Canterbury United claimed South Island bragging rights with a 4-1 away win over Otago United.