Katie Taylor will make her long awaited Olympic debut when she fights for a medal against Natasha Jonas of Great Britain in the quarter-final of the lightweight boxing division.
The Wicklow fighter is guaranteed a medal if she can overcome her British opponent.
By the time Taylor steps into the ring at 2.30pm, Ireland could be celebrating its first gold medal of the games, when Annalise Murphy takes part in the Medal Race of the Laser Radial sailing.
The Dun Laoighaire sailor begins the race at 1pm in third position knowing a win will secure her a gold medal.
However, celebrations are already underway in the Team Ireland camp after Mullingar boxer John Joe Nevin last night secured the first Olympic medal for Ireland.
His 19-13 victory last night over Mexico's Oscar Valdez Fierro guarantees a bronze medal.
An emotional Nevin dedicated his victory to his cousin David who died in February and now faces the Cuban World number one on Friday.
Paddy Barnes and Michael Conlan are also chasing bronze later in the week.