The decline was due to the slowed US market, weak Chromebook demand and supply chain issues, which impeded Lenovo's ability to supply PCs to enterprise customers.
These factors also contributed to HP's 4 per cent year-over-year decline. However, HP's decline was tempered by robust growth in the Asia-Pacific market.
HP with 21.1 per cent share was second, followed by Dell with 19.5 per cent global market share in Q4.
Worldwide PC shipments totalled 88.4 million units in the fourth quarter of 2021, a 5 per cent decrease from the fourth quarter of 2020.
This is the first year-over-year decline following six consecutive quarters of growth. For the year, PC shipments reached 339.8 million units in 2021, a 9.9 per cent increase from 2020, said the report.
"A sharp decline in the US PC market, caused by ongoing supply chain issues and the collapse in demand for Chromebooks, drove this quarter's slowdown," said Mikako Kitagawa, research director at Gartner. "This likely signifies the end of the massive and unexpected growth in PC demand triggered by the pandemic.
The top three vendors in the worldwide PC market remained unchanged in the fourth quarter of 2021.
Dell gained market share this period after notching a fifth consecutive quarter of growth.
Shipment volume exceeded 17 million units for the first time in the company's history, led by strong performance in Latin America, EMEA and Asia Pacific.
"The pandemic significantly changed business and consumer PC user behaviour, as people had to adopt to new ways of working and living," said Kitagawa.