The change in ranking is said to be a combined effect of strong sales of Apple's iPhone 11 lineup and the impact of Huawei's trade ban in the United States.
Despite being blacklisted by the U.S. government in the middle of the second quarter this year, Huawei has managed to ship 60 million handsets, which is around the same amount it shipped in the previous quarter, according to data from Gartner.
However, as the trade ban drags on, Huawei is expect to see sales slide over the second half of this year. Gartner estimates that shipments could fall to about 50 million units in the third quarter, before bouncing back to 60 million units going into the holiday period.
According to IDC, Apple shipped 36 million iPhones in Q1 2019. Sales are said to have dropped to 34 million in the second quarter, with an expected slide to 30 million units in Q3 as people waited for Apple's next-generation flagship devices, iPhone 11, iPhone 11 Pro, and iPhone 11 Pro Max.
But with reports of higher-than-expected sales of its iPhone 11 lineup both domestically and abroad, Apple could see its handset shipments reach 70 million units in the fourth quarter, which would exceed the 60 million units Huawei is expected to ship in Q4 2019.