Grand Slam champions were the story of the day session on Day 1 at the Guadalajara Open Akron, as Bianca Andreescu, Victoria Azarenka and Petra Kvitova put in strong performances to lead Monday's early winners.

Azarenka kicked off the day's play in the Akron Tennis Stadium with a 6-4, 6-2 win over lucky loser Elina Avanesyan, and Andreescu followed her into Round 2 with a 6-2, 6-4 win over Switzerland's Jil Teichmann.

Azarenka was expected to play against China's Zhang Shuai, but Zhang withdrew before the match due to illness. Avanesyan lost to Linda Fruhvirtova in the final round of qualifying, but the 20-year-old got a second chance to play in her first WTA 1000 event on hard courts.

Highlights: Azarenka def. Avanesyan

Azarenka moves through to an intriguing second-round match with No.1 seed Paula Badosa. They've split two prior meetings. Last autumn, Badosa won a marathon final at the BNP Paribas Open, but Azarenka was a straight-sets winner in January in Adelaide. 

Guadalajara 1000: Andreescu off and running with win over Teichmann

Andreescu eyes strong finish: Already eyeing Guadalajara as a tournament she was hoping to excel to end her season last week in San Diego, Andreescu was off and running quickly against Teichmann. 

The Canadian never trailed over the course of 80 minutes. Andreescu broke Teichmann the first three times she served in the match and also broke the Swiss in the first game of the second set. 

Words from the winner: The 2019 US Open champion ultimately handled both an opponent who's given her trouble in the past and tricky conditions at higher altitude in Mexico that's she's never experienced before.

Andreescu is making her debut in Guadalajara this week. It's a challenge she says she relished. 

"I definitely like the atmosphere here," Andreescu said. "I think the altitude helps me in a way, especially when I'm hitting winners. I feel like it just drags [the ball] around, which I actually like. I just wanted to come out, stay positive and give everything I have. 

"I'm very happy with the consistency. Sometimes, I could've went for more, but I chose to be a little bit more safe. I didn't want to go for too much ... there's a good balance. I think my serve went really well today, my return, and just fighting until the end, as well."

Up next: Andreescu's win against Teichmann improved her record against left-handed players to 10-0. She'll have another up next in the former of two-time Wimbledon winner and No.16 seed Petra Kvitova. Kvitova came from 3-1 down in the opening set in a 6-3, 7-5 win over American Bernarda Pera.