The United States defeated Haiti at the CONCACAF Women's Olympic Qualifying Championship final tournament ©Getty Images

The United States began their Confederation of North, Central American and Caribbean Association Football Women's Olympic Qualifying Championship final tournament campaign with a comprehensive victory against Haiti. 

The US, four-time world and Olympic champions, took on Haiti at the BBVA Stadium in Houston.

They started off well, with Christen Press meeting a Lynn Williams cross to score in the opening two minutes. 

Despite the early lead, the US struggled to break Haiti down again in the first half, conceding a Haitian goal that was then disallowed. 

FIFA World Cup Golden Boot and Ball winner Megan Rapinoe was brought on for Press in the second-half, immediately making an impact with a corner that was successfully converted by Williams in the 67th minute to make it 2-0. 

Rapinoe earned another assist just six minutes later, with Lindsey Horan scoring this time. 

Carli Lloyd sealed the victory in the dying minutes of the match, with the US triumphing 4-0. 

Costa Rica overwhelmed Panama 6-1 in the other Group A game, with Daphne Melissa Herrera Monge and Priscilla Chinchilla scoring twice each. 

Raquel Rodríguez converted a penalty, while captain Shirley Cruz also got on the scoresheet. 

Katherine Lineth Castillo Macias grabbed Panama's solitary goal. 

Group B is due to under way tomorrow at H-E-B Park in Edinburg, with Canada taking on tournament debutantes Saint Kitts and Nevis and Mexico coming up against Jamaica. 

The top two teams at the end of the competition earn a place at this year's Olympic Games in Tokyo.