The NRMA Insurance Western Sydney Wanderers have secured bragging rights in the 15th Sydney Derby after defeating Sydney FC 1-0 at ANZ Stadium on Saturday night.
A first-half Brendon Santalab strike snatched all three points for the Red & Black, who claimed their first Derby victory in more than three years.
The game began at a predictably frantic pace and it was the Wanderers' Jaushua Sotiro who had the first sight of goal.
The youngster latched onto a Mitch Nichols through ball though couldn't get enough on his shot to trouble Danny Vukovic in goal.
After his heroics in the last Derby, Vedran Janjetovic was once again in fine form, doing well to keep out efforts from Alex Brosque and Filip Holosko.
Nico Martínez should've broken the deadlock when he found space on the edge of the six-yard box after a cross from Nichols but the Argentine's shot was blocked at the death.
The Wanderers would find the opner soon after in 26th minute of the match with Santalab rising to the Derby occasion.
A cross from Nichols found the striker, who quickly turned and fired through Vukovic's legs to put the home side up 1-0.
Both sides had fantastic chances to find the net in the second half but were denied by some fantastic goalkeeping: Vukovic doing superbly to deny Martinez and Sotirio, while Janjetovic pulled off an amazing double-save to stop Bobo and keep his side ahead.
The Wanderers would hold out to deny their cross-city rivals' dream of an unbeaten season and seal an all-important win that cements them in the top 6.
The Red & Black will now quickly turn their attention to Tuesday night's 2017 Asian Champions League opener against Urawa Red Diamonds at Campbelltown Stadium.