Roger Federer comes through Vasek Pospisil test

Roger Federer has advanced through to the last 16 of the Cincinnati Open after edging past Vasek Pospisil in three sets.

The world number three looked on course for a simple passage through to the next round when he edged the opening set on a tie-break, but his Canadian opponent found a way back into the match in the second.

After the opening 10 games were dominated by serve, Pospisil broke Federer's serve to take the match into a decider as the world number 46 threatened to pull off a major shock.

However, Federer regained his composure to break twice in the third to record a 7-6 5-7 6-2 win to register his 300th victory at a Masters Series event.

Federer will now play either Roberto Bautista Agut or Gael Monfils on Thursday.