Williams, who was facing Kerber for the fifth time on the WTA Tour, was never really troubled by the German, who was unable to find a way past the American's powerful serve.
It started well for the world number one, who broke Kerber to take a 4-1 lead. After saving one break point, she again broke to take the first set 6-2.
With the pattern of play established, Williams was able to control the tempo of the match and secured another break of serve to take command in the second.
After holding serve, she needed just one match point to confirm a 6-2 6-2 win.