China's President called the progress China had made under his watch "truly remarkable" but said more needed to be done as the country moves toward a goal of "national rejuvenation" -- a phrase he used repeatedly during the more than three-hour speech.
"Our party, our people, our forces, and our nation have changed in ways without precedent," he said from the Great Hall of the People in the heart of Beijing on the opening day of the weeklong meeting.
But Xi made it clear that China's future path wouldn't emulate the West, saying he wouldn't "mechanically copy the political systems of other countries."
"No one should expect China to swallow anything that undermines its interests," Xi said.
Standing at a podium before more than 3,000 delegates and guests, and a televised audience of millions, Xi said China's "international standing has risen as never before," although he was short on specifics when it came to foreign policy.
The Chinese leader didn't mention the escalating tensions between its ally North Korea and the US, which Beijing has been working with to pressure Pyongyang to halt its nuclear program.
However, as Xi listed the country's accomplishments, he briefly touched on the South China Sea, where China has reclaimed land, turning reefs and sandbars into military bases in defiance of an international court ruling.
Tigers, flies, foxes
The 19th National Congress of the Communist Party of China will see President Xi formally granted a second five-year term as the party's general secretary and a new generation of senior Chinese leaders anointed.
The meeting will also chart the country's future course in a world where China's reach is now extending -- and being felt -- further than ever before.
Domestically, Xi detailed China's economic accomplishments in the last five years, including lifting 60 million people out of poverty, improving living standards, education, enhancing law, order and national security.
He said the crackdown on corruption that's been a hallmark of his leadership had swept through all levels of the party.
"No place has been out of bounds and no grounds left unturned. No tolerance has been shown in the fight against corruption. We have taken firm action to take out tigers, swatted flies, and hunted down foxes," he said, using shorthand for officials big and small.
Xi's anti-graft campaign has brought down more than a million officials,
according to state media, including senior politicians who were often viewed as Xi's rivals.
In addition to his focus on corruption, since taking power in 2012 Xi has launched an unprecedented crackdown on free speech and dissidents, and radically overhauled the People's Liberation Army, the world's largest fighting force.
The audience, which broke into applause at regular intervals, included former Chinese Presidents Hu Jintao and Jiang Zemin, who was spotted looking at his watch repeatedly as the speech dragged on and eventually lasted nearly three and a half hours.
Jiang himself took far less time in 2002, telling attendees his report "has been printed and distributed to all delegates, so I'm not going to read the entire report, I'll just highlight the important points."
Pictures shared on social media showed Xi's marathon address being watched across the country in workplaces, hospitals, prisons and schools -- even kindergartens.
Wil Xi follow in Putin's footsteps?
The congress is being seen as a referendum on Xi's success in positioning himself as China's unquestioned political supremo.
At the congress, Xi may seek to cement his standing by revising the party charter to include "Xi Jinping Thought" as one of the party's guiding theories, elevating his stature to that of Chairman Mao Zedong who founded the People's Republic of China in 1949. China's previous two presidents haven't had their ideas enshrined in the constitution in this way.
Some have speculated that Xi may also seek to stay in power beyond 2022, breaking a tradition followed by his two predecessors and emulating Russian President Vladimir Putin.
Xi is expected to emerge from congress stronger than ever, which could have international ramifications given that China is key to US efforts to rein in North Korea. Trump is scheduled to visit Beijing in November shortly after the Congress ends.
Security in Beijing, and the rest of the country, has been extremely tight as the congress gets underway. Already-strict internet censorship has been beefed up, with the widespread deletion of "sensitive content" on social media.
With the world "in the midst of complex changes," Xi also positioned the country as a "torch bearer" for ecological issues.
The country has, by default, emerged as an unlikely environmental leader after US President Donald Trump quit the Paris climate accord in June.
"There is a fundamental improvement in the environment and the goal of building a beautiful China is basically attained."
Xi also warned against "separatist activity" and had strong words for Taiwan, which is regarded as a breakaway province, saying that reunification was key to realizing China's "national rejuvenation."
"China will never pursue development at the expense of others' interests, but nor will China ever give up its legitimate rights and interests," Xi said.