It was a loss that made the biggest news at the National Bank Open in Toronto on Wednesday as Serena Williams, one day after announcing she plans to step away from tennis to focus on her family, was defeated in the second round by Belinda Bencic of Switzerland.

In a match that lasted one hour and17 minutes, No. 12 seed Bencic defeated Williams in straight sets, 6-2, 6-4.

Although Williams started the match with an ace, she was not able to keep up with Bencic throughout much of the match.

"I wish I could have played better," Williams said, "but Belinda played so well today."

A leg injury has sidelined Williams for much of the past year, limiting her to only three outings in the past 12 months.

After the match, Williams told the packed stadium, "I'm terrible at goodbyes, but goodbye, Toronto!"

In other matches Wednesday, top seed Iga Swiatek of Poland breezed into the next round while No. 10 Coco Gauff needed nearly three hours to beat the Wimbledon champion to advance.

Second-seeded Estonian Anna Kontaveit also fell, and No. 4 seed Paula Badosa of Spain and No. 5 Ons Jabeur of Tunisia were eliminated after retiring from their respective matches.

Gauff needed two hours and 49 minutes to defeat Elena Rybakina of Kazakhstan 6-4, 6-7 (8), 7-6 (3) in the Round of 32.

Gauff squandered four match points in the second set but eventually defeated Rybakina in the deciding third set. Gauff survived 13 double faults in the win.

Swiatek, by contrast, posted a 6-1, 6-2 win over Australian Ajla Tomljanovic 6-1, 6-2 in 64 minutes.

This is just the second main draw appearance for Swiatek in Toronto. She reached the third round in 2019 as a teenager before falling to then-No. 2 seed Naomi Osaka.

"It really gave me extra motivation," Swiatek said. "Because even though I lost this match against Naomi I remember I was just happy that I could play such a tight match against her. She was World No. 1 back then so it was a big deal for me for sure."

Kontaveit was ousted 6-4, 6-4 by Jil Teichmann of Switzerland in one hour and 27 minutes. Kontaveit had her chances but converted just 2 of 8 break point opportunities. Teichmann broke Kontaveit four times in six tries.

Badosa was down 7-5, 1-0 when she was forced to retire against Yulia Putintseva of Kazakhstan. Jabeur also dropped her first set before retiring down 2-1 in the second set to Qinwen Zheng of China.

Sixth-seeded Aryna Sabalenka of Belarus defeated Sara Sorribes Tormo of Spain 6-4, 6-3 in one hour and 50 minutes to advance.

Hometown favorite and 13th-seeded Canadian Leylah Fernandez fell to Brazil's Beatriz Haddad Maia 7-6 (4), 6-1. But later Wednesday night, Canada's Bianca Andreescu advanced by beating France's Alize Cornet 6-3, 4-6, 6-3.

Other seeded players to advance included No. 7 Jessica Pegula, No. 8 Garbine Muguruza of Spain, No. 14 Karolina Pliskova of the Czech Republic and No. 15 Simona Halep of Romania. No. 16 Jelena Ostapenko of Latvia lost to Alison Riske-Amritraj 7-6 (2), 0-6, 7-5.