The former world No.5 broke Williams’ serve twice in the first set, but had her own broken four times, as the overwhelming Australian Open favourite went on to win 6-2 6-2.
Their heavily delayed night session match is being followed by Novak Djokovic’s clash with Jo-Wilfried Tsonga, in a rematch of the 2008 men’s final.
Djokovic took the opening set against the Frenchman 6-3.
An epic clash between Stan Wawrinka and Milos Raonic which lasted over four hours, followed by a three-setter between world No.1 Simona Halep and American Sofia Kenin, saw the start of the night session delayed by an hour and a half.
Follow Night 4 live below and recap all the daytime action here.
All of the scheduling issues meant the start of Williams v Bouchard wasn’t shown on either of the Nine channels broadcasting the tennis; Aussie Alex Bolt v Gilles Simon and Alexander Zverev v Jeremy Chardy, perhaps more surprisingly, taking priority.
Many tennis fans took to social media to display their displeasure.
The match was put on the main Nine channel with Williams up 4-1 in the first set, after the conclusion of Bolt’s win over Simon.
These big-name encounters are unusual for this stage of the tournament but a result of Bouchard and Tsonga’s slide down the rankings due to form and injury struggles.
German world No.4 Alexander Zverev also resumes his campaign while Aussie surprise packer Alexei Popyrin has defeated Austrian seventh seed Dominic Thiem.
Sore loser flips the bird0:32
EVENING ORDER OF PLAY
Rod Laver Arena
16-Serena Williams (USA) def Eugenie Bouchard (CAN), 6-2 6-2
1-Novak Djokovic (SRB) v Jo-Wilfried Tsonga (FRA)
Margaret Court Arena
4-Alexander Zverev (GER) v Jeremy Chardy (FRA)
Johanna Konta (GBR) v 18-Garbine Muguruza (ESP)
Alexei Popyrin (AUS) def 7-Dominic Thiem (AUT), 7-5 6-4 2-0 ret
Follow Day 4 of the 2019 Australian Open in our live blog below.
— with AAP