Clarke plotted the downfall of his former side (Dublin) in a winner-takes-all clash at Naomh Mearnóg.
The Westerners ran out 1-10 to 0-8 winners against the Sky Blues to finish fourth in the table – a result that sets up a Division 1 semi-final meeting with champions Monaghan.
Mayo had to come from behind to get the result, as Clarke’s charges trailed 0-5 to 0-6 at half-time.
The westerners were three points behind approaching half-time before Aileen Gilroy and Deirdre Doherty notched scores to keep them in touch.
With the breeze at their backs for the second half and ace forward Cora Staunton in fine form, they began to exert a growing influence.
And Staunton was involved in the crucial goal as Dublin goalkeeper Cliodhna O’Connor struggled to deal with the Carnacon star’s lengthy free and Niamh Kelly netted the loose ball.
Dublin responded well after that setback but Mayo held out for that spot in the last four, despite Natalia Hyland pointing a 60th minute penalty for the home side.
Meanwhile, Cork and Laois will meet in the other semi-final.
All-Ireland champions Cork were boosted by the return of experienced trio Deirdre O’Reilly, Angela Walsh and Nollaig Cleary for Saturday’s 7-23 to 0-3 demolition job on Donegal at Cork IT.
Cork led by 3-11 to 0-1 at half-time with Walsh, Rhona Ni Bhuachalla and Emma Farmer (penalty) scoring the goals.
Sarah Harrington collected a brace in the second half as the hosts tacked on four more goals, with Donegal on the receiving end of a 41-point mauling.
Elsewhere, Sinead Doogue and Martina Dunne netted for Laois but already-relegated Meath still recorded their first victory of the season as they ran out 3-16 to 2-13 winners in Summerhill. And Monaghan made is seven wins from seven with an emphatic 6-16 to 1-4 victory against Tyrone in Clones.
Ciara McAnespie scored a hat-trick, Caoimhe Mohan a brace and Therese McNally notched the other goal for Gregory McGonigle’s rampant side.
Elsewhere, there was drama in Division 2 as Clare avoided relegation with an impressive 7-8 to 0-8 victory against Westmeath in Kinnegad.
Waterford’s 2-11 to 2-8 win over Kildare on Saturday left Clare knowing that they had to win on their travels to stay up.
And the Clare girls produced a big win to condemn Waterford to Division 3 in 2014.
In the semi-finals, Kerry will play Kildare and Galway will take on Westmeath.
In the third tier, Wicklow were relegated from the Division after losing by 1-6 to 4-18 at home to Wexford, who stay up.
And in the divisional semi-finals, Armagh will play Leitrim and Down take on Tipperary. In Division 4, Offaly, Roscommon, Limerick and Antrim occupy the top four positions.