Poland's Iga Swiatek replaced newly retired Ashleigh Barty to become the world's No. 1 women's tennis player on Monday.

The 20-year-old celebrated her new status in style earlier Sunday, winning the Miami Open with a straight-sets victory over four-time Grand Slam champion Naomi Osaka.

Swiatek's victory made her only the fourth women's player in history to win the Indian Wells and Miami tournaments often dubbed the "Sunshine Double," back-to-back.

In her reaction, Swiatek said she cried for 40 minutes after learning of three-time Grand Slam champion Barty's shock retirement from tennis last month.

"I was crying for 40 minutes," Swiatek told the BBC on Monday. "Mainly, it was because of Ash's retirement. I didn't know it was going to happen and it really surprised me.

"I always had this vision that we would all play until we are 35 or something, until our bodies are so tired that we can't anymore."

The former French Open champion already holds a substantial lead over second-ranked Czech Barbora Krejcikova.

Miami runner-up Osaka jumped up 42 places to move into 35th in the rankings. The Japanese star will be hoping to secure seedings for the remaining three majors of the year.

WTA Top 10

1. Iga Swiatek (POL) 6,711 pts (+1)

2. Barbora Krejcikova (CZE) 4,975 (+2)

3. Paula Badosa (ESP) 4,970 (+3)

4. Maria Sakkari (GRE) 4,705 (-1)

5. Aryna Sabalenka (BLR) 4,657

6. Anett Kontaveit (EST) 4,511 (+1)

7. Karolina Pliskova (CZE) 4,197 (+1)

8. Danielle Collins (USA) 3,151 (+3)

9. Garbine Muguruza (ESP) 3,070

10. Ons Jabeur (TUN) 2,975