Jan 5 (Reuters) - Citigroup analysts on Wednesday raised their S&P 500 (.SPX) price target for the end of 2022, estimating it to breach the 5,000 level for the first time, as the brokerage expects strong corporate earnings to continue this year. Earnings results from S&P 500 companies in 2021 blew past analyst estimates to deliver year-on-year growth in the first three quarters of 52.8%, 96.3% and 42.6%, respectively, according to Refinitiv, which currently sees fourth-quarter annual earnings growth of 22.3%. read more Companies, consumers and the broader economy largely thrived in 2021, helped by several factors such as a transfer of power in the U.S. government, the "meme stock" phenomenon, generous fiscal and monetary stimulus, booming demand and price spikes. Citigroup analysts raised their price target for the S&P 500 to 5,100 from 4,900 set in October, cautioning that a U.S. Federal Reserve policy tightening could pose valuation headwinds. The S&P 500 rose about 27% in 2021, gaining more than 3% in the last two months alone. The index closed at 4793.54 on Tuesday. read more Upcoming quarterly results and 2022 outlook of companies could provide the cushion for growth, despite COVID-19 and supply chain woes, Citigroup analyst Scott Chronert said.