Sam Kerr's Western New York Flash have taken out the inaugural National Women's Soccer League premiership.

The final round of matches saw the premiership race still wide open with all Top 4 sides (FC Kansas City, Western New York, Sky Blue FC and Portland Thorns) capable of capturing the title.

Western New York clinched the title after FC Kansas City conceded late in stoppage time to lose 2 -1 to the Chicago Red Stars.  The result left the Flash, Kansas City and the Portland Thorns all on 38 points.

However, with the head-to-head tie breaker employed, Flash's results over Kansas City and a superior goal difference saw the inaugural premiership head to Rochester, New York.

Despite coming into Round 22 sitting in second place behind FC Kansas City, Kerr and her Flash teammates put the pressure on the ladder leaders with a hard fought 2 – 1 win over Kyah Simon's Boston Breakers.

Kerr has had a stellar season | (Credit: Caitlin Murray / @WosoCait) Kerr has had a stellar season | (Credit: Caitlin Murray / @WosoCait)

The West Australian was instrumental in that win with a stellar performance on the wing highlighted by a lovely volley to open Western New York's scoring in the 23rd minute.  Abby Wambach headed the Flash further ahead in the 26th minute.  Rhian Wilkinson pulled one back for the Breakers in the second half but Flash held on for the three points.

In Seattle Emily van Egmond's Seattle Reign were unable to finish their season on a high note with a double from Portland Thorns captain Christine Sinclair cancelling out Megan Rapinoe's third minute opener.

With former coach Tom Sermanni in the stands, van Egmond and the Reign put in a good performance creating numerous scoring opportunities but an 83rd minute goal from Sinclair proved the difference.

Earlier this morning Sky Blue FC ended their season with a 1 – 1 draw with Washington Spirit.  With Lisa De Vanna experiencing hamstring tightness late in the season and a finals berth already confirmed, Sky Blue did not risk their influential striker ahead of a semi final appearance this weekend.

Kerr now has the opportunity to win her second championship, in a second competition this year following on from Sydney FC's W-League win this January.

The NWSL finals sees Kerr's Western New York host Lisa De Vanna and Caitlin Foord's Sky Blue FC, with FC Kansas City hosting the Portland Thorns FC this Sunday (Australian time).