Photos: Slam champs Rybakina, Ostapenko advance in Toronto

A packed Monday schedule at the National Bank Open presented by Rogers saw numerous Grand Slam champions and former World No.1 players hit the Toronto hard courts.

Along with victories by major champions Serena Williams, Simona Halep and Sloane Stephens, here are some of the others who played their first-round matches on Day 1:

Elena Rybakina def. Marie Bouzkova 7-5, 6-7(3), 6-1

Rybakina picked up her first match-win since she charged to her first Grand Slam title at Wimbledon last month, but it came in lengthy fashion. Rybakina needed exactly three hours to overcome in-form Bouzkova.

Bouzkova, who was a 2022 Wimbledon quarterfinalist and is coming off her first career title in Prague two weeks ago, took a set off of Rybakina for the first time in their rivalry. However, Rybakina swept through the third set and is an undefeated 3-0 against Bouzkova.

Rybakina is currently in second place on the 2022 ace leaderboard, and the reigning Wimbledon champion added six aces today, bringing her total for the season up to 231. Caroline Garcia is currently the ace leader with 238 for the year.

Jil Teichmann def. (WC) Venus Williams 6-2, 6-3

Teichmann, the World No.21 from Switzerland, took 1 hour and 15 minutes to eliminate seven-time Grand Slam singles champion Williams. Teichmann converted six of her 10 break points to prevail and set up a second-round meeting with World No.2 Anett Kontaveit.

Former World No.1 Williams, at age 42, was playing just her second singles match back on tour after a nearly year-long absence. 2014 National Bank Open finalist Williams fell in her first match against a Top 25 player since a loss to Ons Jabeur at Wimbledon last year.

(16) Jelena Ostapenko def. Anhelina Kalinina 6-4, 6-2

Ostapenko, the 2017 Roland Garros champion, took 1 hour and 13 minutes to improve to 3-0 against Kalinina on tour. Ostapenko also beat Kalinina en route to her Junior Wimbledon title in 2014.

Ostapenko won 81 percent of points behind her first service, and claimed two-thirds of points when returning the Kalinina second serve. Kalinina had six aces but also 11 double faults in the match.

(14) Karolina Pliskova def. Barbora Krejcikova 6-3, 6-4

In a battle between Top 20 players, former World No.1 Pliskova ousted 2021 Roland Garros champion Krejcikova in an hour and a half.

Pliskova, last year's runner-up when the event was held in Montreal, is now 4-0 against her fellow Czech Krejcikova. Pliskova won nearly 70 percent of points returning the Krejcikova second serve, slammed seven aces, and converted five of her six break points.

Krejcikova fought back from 5-1 down in the second set, reeling off three games in a row and forcing Pliskova to serve for the match for a second time at 5-4. But Pliskova regrouped and executed a commanding love hold to grab the win.

Alison Riske-Amritraj def. Petra Kvitova 6-2, 4-6, 6-3

World No.33 Riske-Amritraj battled past 24th-ranked Kvitova, the two-time Wimbledon champion, in just under 2 hours. Riske-Amritraj now has a 3-1 lead in her rivalry with 2012 National Bank Open champion Kvitova.

Riske-Amritraj finished the match with a 50 percent success rate behind her second serve, while Kvitova won only one-quarter of her second-service points. Kvitova's six aces were canceled out by her six double faults, and she never held a break point in the final set.