The Sky Blues came out looking dangerous but struggled to find the back of the net in the first half, despite several perfectly placed balls from midfielders Sarah Hunter and Mackenzie Hawkesby.
They quickly atoned in the second half, however, as Lowe scored within five minutes of the break thanks to a well-weighted through-ball from Vine on the right wing.
Only 10 minutes later the pair were on show again as Vine accelerated to the corner of the box and cut back to the goal line to find Lowe, who sneaked the ball past United goalkeeper Hillary Beall.
On the other wing, Sky Blues star Princess Ibini surged down the pitch but repeatedly struggled to gain inroads to the box thanks to some high-pressure defending from United's Angela Beard and Alana Ceme.
But Ibini's hard work paid off in the 81st minute when a deep pass from captain Natalie Tobin into the penalty area was swept up by the forward, making it 3-0.Â
The game was anything but mellow, and after a frustrating first half both sides came out with a fiery point to prove, resulting in yellow cards for Sydney's Deborah-Anne de la Harpe, Hunter, Vine, Tobin and United's Julia Sardo.
Tobin, filling in for skipper Madison Haley after she was ruled out with a hip injury, had a spirited second half and was sent off in extra time for a second yellow card.
Seconds later, a floating ball into the home side's penalty area from United's Sydney Cummings resulted in a Sky Blue panic that led to defender Charlotte McClean colliding head-on with Whyman.
The flurry of injuries and yellow cards meant all of Sydney's bench had a run, including 15-year-old Indiana Dos Santos in her A-League debut.
Strong performances from United's forward Hannah Keane and defender Angela Beard were unfortunately backed by a lacklustre squad that struggled to keep up with Sydney's quick pace.
United remain on top but are just three points ahead of Sydney, who have two games in hand.
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