World number seven Juan Martin del Potro has beaten Nikolay Davydenko in the second round of the Cincinnati Open.
The efficient Argentine did not have it all his own way against the ageing Russian but managed to strike at crucial moments to take a 7-5 7-5 victory.
Davydenko, who has returned to the style of racquet that saw him win the World Tour finals in 2009, showed signs that his days on court are not quite numbered, but he still could not deal with Del Potro's devastating power.
After receiving a bye in the first round, the 2010 US Open champion will now face the winner of Feliciano Lopez and Jeremy Chardy in the third round.
