Juan Martin del Potro overcame the challenge of veteran Tommy Haas to move into round three of the Cincinnati Open this evening.
The opening set was a fairly even contest as both players held their first five service games each.
However, Argentine Del Potro then claimed a decisive break of Haas's serve to go 6-5 in front, before serving out to take a one-set lead.
World number nine Del Potro appeared to gain confidence from his success and produced a string of forehand winners in the second set to which Haas had no answer.
The 23-year-old eventually ran out a 6-2 victor to book his place in quarter-finals, where he will face Viktor Troicki.
