Republic of Ireland stars Leanne Kiernan and Megan Campbell are heading for the Women's FA Cup final following semi-final wins for their respective sides.
Kiernan's West Ham overcame a penalty shootout against Reading to book their spot in the decider on 5 May, while Campbell's City edged out holders Chelsea.
The Hammers sealed a spot in the final for the first time after a 4-3 penalty shootout victory over Reading at Adams Park following a 1-1 draw.
The Ireland striker started that game for West Ham before being substituted after 58 minutes.
Rachel Furness' header four minutes after the interval was cancelled out by Alisha Lehmann just before the hour, but Fara Williams then saw her spot-kick for the Royals hit a post.
With no goals in extra-time, the shootout went to sudden death as Lauren Bruton and Rakel Honnudottir for Reading and Brianna Visalli and Kate Longhurst for West Ham missed their penalties.
Jade Moore then saw her spot-kick saved by Anna Moorhouse, allowing Cho So-hyun to score to secure victory for the Hammers.
Meanwhile, Campbell was among the substitutes as Magdalena Eriksson's unfortunate own goal in added time sent Man City through to FA Cup final.
The tie looked to be heading towards extra-time between two sides who have met four times in this competition in the last five years before City set up a Wembley date against West Ham next month in unlikely fashion.
Under no pressure, Eriksson inadvertently turned Demi Stokes' cross past Blues goalkeeper Ann-Katrin Berger in the second minute of injury time at City's Academy Stadium.