Neither Li nor Halep will be playing at the Rogers Cup in Montréal next week - Li has pulled out due to a right knee injury, and Halep was never entered. But while Halep has no points to defend as she didn't play it last year, Li made it all the way to the semifinals of the Premier-level tournament last year.
Once those points fall off, she will dip down and surrender World No.2 to WTA Rising Star Halep.
After a breakthrough 2013 that saw her win her first six WTA titles and go as high as No.11 on the year-end rankings, Halep has continued her rise in 2014, picking up two more WTA titles at Doha and Bucharest and reaching the quarterfinals or better at a Grand Slam for the first three times - the quarterfinals of the Australian Open, the finals of the French Open and semifinals of Wimbledon.
"I have worked very hard to become the best tennis player I can possibly be," Halep said. "This year has been an amazing year so far and to move to No.2 in the rankings is a great accomplishment.
"There is a lot of tennis still to be played this year and I look forward to the upcoming hardcourt season," she added. "And I remain focused on trying to qualify for the WTA Finals in Singapore.
"Thank you to all my fans and my team for the continued support. I'll see you in Cincinnati."
The Romanian will become the 33rd player in WTA history to reach the Top 2. Here are the others...
The 11 Players With A Career-High Of No.2
Virginia Wade, Billie Jean King, Andrea Jaeger, Conchita Martínez, Jana Novotna, Anastasia Myskina, Svetlana Kuznetsova, Vera Zvonareva, Petra Kvitova, Agnieszka Radwanska and Li Na.
The 21 World No.1s
Chris Evert, Evonne Goolagong Cawley, Martina Navratilova, Tracy Austin, Steffi Graf, Monica Seles, Arantxa Sánchez-Vicario, Martina Hingis, Lindsay Davenport, Jennifer Capriati, Venus Williams, Serena Williams, Kim Clijsters, Justine Henin, Amélie Mauresmo, Maria Sharapova, Ana Ivanovic, Jelena Jankovic, Dinara Safina, Caroline Wozniacki and Victoria Azarenka.