Much like in the aforementioned 06 64 62 loss north of the border, Williams came out firing - in roughly half an hour she was up 61 20. Flipkens put up some serious resistance at that moment, catching up to 2-all and taking Williams to six deuces in the next game, but Williams got the control back just in time, sneaking that game out then running away with it against the No.12-seeded Belgian, 61 62.
"In Toronto I started out really strong and it didn't end up as well as I would have liked," Williams said. "But my serve was a lot better today. In Toronto I wasn't really feeling that great about my serve. Honestly, I think that made a huge difference. I think I was serving in the 40 percentages in all of my matches this summer, so it was very challenging - but you can only go up. I've worked on it a lot.
"I just kind of held on to that second set. She played some competitive games and dug out some points you kind of think are going to go your way - that shows why she's been playing so well this year."
Not many seven-time Grand Slam champions and former World No.1s have been doubted as much as Williams has in recent times - her comprehensive win over the World No.14 serves some major notice.
"I stay positive because I know I can play great tennis. Sometimes you just have to go through more than what you want to go through. Sometimes you have to have losses. When I have losses, it always motivates me a lot to do better and to work harder. I realize I haven't had a lot of chances to play healthy this year, and I've had injuries and what have you, so I'm just going to have to keep working my way into it, maybe more than some of the other players, but I know I can do that. That's what it is."
Another player from Williams' generation, James Blake, announced Monday that this would be his last tournament. Williams shared her thoughts on the former World No.4 in her post-match presser.
"Obviously the US Open was a special place for him. I understand how he would want to end here. I think he still has a lot of great tennis in him, but he's decided that now is the time for him. He has a family now, so those are important priorities from what I hear. He's ready, so all we can do is support him. Hopefully he will be able to contribute to tennis outside of the game, however he chooses.
"What I admired about him was how he gave back, using his tennis career and celebrity to give back, especially to cancer, because his dad passed. And also the excitement he brought to the game. I think he brought a lot of people into tennis. It's always great and also sad to lose someone who helps grow the game - people are always interested in James, so that's what I'm going to miss about him."
Williams' second round opponent will be Zheng Jie, who beat Kiki Bertens later on, 61 63. Williams beat Zheng in their only previous encounter, though it was nine and a half years ago at Miami in 2004.