Venus Williams gave a commanding performance with little sister Serena looking on as she trounced qualifier Mandy Minella of Luxembourg to reach the fourth round of the US Open.

The third-seeded Williams needed two service games to find her bearings and then raced to a 6-2 6-1 victory as the 185th-ranked Minella managed to win just a single game on serve.

Williams won with style, wearing a sparkling, short black dress with revealing cut-outs in the back. Not to be outdone, world number one Serena Williams, sidelined with a foot injury, wore a red dress in the player's box.

Two-time former US winner Williams will next play 16th seed Shahar Peer of Israel, who beat Flavia Pennetta of Italy, the 19th seed, 6-4 6-4 to advance.