Kerber, who was beaten by Serena Williams in last year's final, is known for her fighting qualities and needed to show all of them to beat Rogers in two hours and 17 minutes.
The German world No1 has spoken openly about her unease with being up there to be shot at and looked as much as Rogers capitalised on her opportunity to take chunks out of the world No1 in a tournament where she has previously never won a game.
With her forehand starting to prove a particularly potent weapon, Kerber duly dominated the second-set tie-break, levelling the match at the second time of asking despite having to delay her serve due to the unwelcome attentions of a wasp.
Next she will face Garbiñe Muguruza, the 2015 runner-up, who breezed through with victory over Sorana Cirstea.
"I think I have to play from the first point good tennis against her", Kerber said Saturday.
The German was the beaten finalist at Wimbledon previous year but has not been in the same form in 2017 and could lose her place at the top of the rankings at the end of this tournament. I'm just going to take care of my next match and we see from there. "And for the first time in my career to have back-to-back years where I have made the second week is exciting".
The former match was called off at 6-2, 3-6, 7-6 (5), 1-6, 6-5, with the 12th seed not wanting to serve as the light faded, though Querrey was happy to receive. I think that's a different kind of pressure that is self brought upon.
The 25-year-old Vandeweghe reached the semifinals of the Australian Open, where she lost to runner-up Venus Williams. I was running better to every single ball.
"It was for sure a really important win for me today, especially because it was a really up-and-down match", Kerber said.
Meanwhile, CoCo Vandeweghe won the All-American matchup with a 6-2, 6-4 victory over Alison Riske. Slovakian Magdalena Rybarikova, who knocked out third seed Karolina Pliskova in the second round, dispatched Lesia Tsurenko of Ukraine 6-2, 6-1 and Croatian Petra Martic beat Zarina Diyas of Kazakhstan 7-6 (6), 6-1. "The last time I played her here, I lost the match, so".