A second-half surge saw Mayo make it three Connacht championships in a row.
Roscommon losing out 14 points to 10 in Dr. Hyde Park as Mayo surged in the third-quarter as the game was level at half-time.
Mayo took the lead after one minute through Oisin Deane. Dean Casey cancelled the lead out four minutes later.
Conor Moriarity restored Mayo's lead with six minutes on the clock. A Dara Currin free levelled the game up six minutes later with Currin putting Roscommon into lead moments later from play.
It took Mayo seven minutes to respond through Morairty for this second point of the day. Kobe McDonald put Mayo a point clear moments later.
Alan Conroy levelled the close game on 25 minutes. Mayo regained the lead four minutes later through a Kobe McDonald free.
However, the teams went in level at half-time after Stephen Tighe with an excellent point from play. The sides tied at five points apiece at half-time.
Dara Currin put Roscommon into the lead three minutes after the break with Oisin Deane and Dean Casey exchanging scores over the next two minutes.
However, this was the marker for a Mayo surge. Evan Walsh (free), Kobe McDonal (free), Oisin Deane and Andrew Quinn finding points inside five minutes as Mayo led 10 points to seven.
Roscommon didn’t give in and Dean Casey and Cathal Enright landed scores to make it a one point game.
However, Joe Forry restored Mayo’s two point lead with 12 minutes to play. Four minutes later Roscommon goalkeeper Patrick Gaynor received a black card and Rosommon had a mountain to climb.
Three Kobe McDonald points (1f) moved Mayo into gear to land a third Connacht title in-a-row. Dean Casey converted a free in the first minute of injury time, but it was Mayo’s day.
Mayo winning out 14 points to 10. Roscommon will meet Munster champions Kerry in the All-Ireland quarter-final.
