The American world No. 1, under an injury cloud heading into the year’s first grand slam, was in control throughout a 6-4, 7-5 win at Rod Laver Arena.

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Williams, a 21-time grand slam champion, has had limited match practice because of knee inflammation during the Hopman Cup. But the defending champion was too good for the hard-hitting Italian Giorgi, the highest ranked unseeded player in the draw.

Williams showed plenty of emotion in the big moments despite rolling out to a 4-1 lead in the first set.

Giorgi managed to stay with Williams until the 11th game in the second set, but the latter broke thanks to a double fault before closing out her win.

STATISTICAL BREAKDOWN

Williams [1] def. Giorgi 6-4, 7-5

ACES

Williams - 9

Giorgi - 7

WINNERS/UNFORCED ERRORS

Williams - 19/22

Giorgi - 17/32

BREAK POINTS WON

Williams - 3/10

Giorgi - 1/1

FIRST SERVE PERCENTAGE

Williams - 53

Giorgi - 45

PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE

Williams - 86/65

Giorgi - 65/48

TOTAL POINTS

Williams - 79

Giorgi - 59