Duff, the 2017 NSW Country Rugby Union women's player-of-the-year, slotted a penalty goal after regular time had expired to secure the Corellas' three-point, 27-24 victory, 10 minutes after converting her own try to draw her side level at 24-all.

That was the third time NSW Country, with nine Central products in their ranks and eight who were in the country championship-winning Blue Bulls side, had been forced to come from behind in the clash.

After leading early they fell behind midway through the first half, they trailed again at half-time and were adrift again late in the second period before Duff's heroics.

Crucially though, they never trailed by more than a converted try and continually hit back quickly in a never-say-die performance, which helped give Duff a chance to seal the nail-biting, tit-for-tat victory.

The Corellas opened the scoring through Shenay Bell just five minutes into Sunday's clash, with Orange Emus and ACT Brumbies halfback Em McDonald's conversion pushing their early lead to seven.

The Sydney-siders hit back though, first drawing level and then going 12-7 ahead with an unconverted try.

McDonald made an impact again as she darted from the back of the ruck and dived over to score, the conversion attempt sailed wide though and again Sydney Gold took back the lead, this time with an uncoverted try on the stroke of half-time.

The two sides traded tries after the restart before Duff injected herself, taking a quick tap from a penalty and catching Sydney Gold napping, nailing the conversion and then slotting the match-winner.

The victory was a bounce-back win for NSW Country too, they were bested 20-12 by Sydney Blue in Saturday's tournament opener, Maya Stewart and Nicole Nathan's tries weren't enough to get the Corellas over the line.

Sydney Blue are poised to claim the cup, they need only to beat Sydney Gold in Monday's metropolitan derby to do so, although there is more on the line than the trophy.

The Chikarovski Cup serves as a pathway to the Buildcorp Super W, primarily through the Waratahs' system but as proven by McDonald and fellow Emus gun Jacky Lyden in 2018, it can provide an opportunity for exposure elsewhere, they picked up ACT contracts last year.

Milika Tuinakauvadra was Emus' other representative as she made her NSW Country debut at the Sydney Academy of Sport, at Narrabeen. The Orange trio was joined by fellow Central West guns Mel Waterford, Krystal and Kim Fyfe, Kenesha Stevens, LillyAnn Mason-Spice and Alanah Ryan.

The metropolitan derby kicks off at 11am on Monday morning.