The Sharif family, however, is unlikely to lose its grip on power for long.
The Supreme Court ruled last week that Nawaz Sharif had been dishonest to Parliament and to the judicial system and was no longer fit for office. He stepped down, quickly selecting his brother to replace him.
Speaking after the vote, Abbasi denied he was only a temporary prime minister. "They say, 'Oh he's only here for 45 days.' I say I may be here for 45 days or 45 hours, but I'm not here to keep the seat warm," he told reporters.
"I intend to work and get some important things done if the cabinet supports me in this."
The younger Sharif, who is currently serving as the chief minister of Punjab, can't take office immediately as he isn't yet a member of Parliament.
He's expected to run in -- and win, handily -- a September by-election for the former prime minister's seat in Punjab, in a district loyal to his brother's Pakistan Muslim League-Nawaz (PML-N) party. The vote is similar to a special election in the United States.
Opposition leader Imran Khan, a cricketer-turned-politician, has criticized the nominations of Sharif and Abbasi, calling them both corrupt and called for cases of corruption against them to be reopened.
So, while Shahbaz Sharif waits to be elected to Parliament, in steps Abbasi.
He needed a simple majority, and as the PML-N, which nominated him, holds 188 of the Parliament's 342 seats, he was expected to win easily.
Following his confirmation, Abbasi will now nominate a cabinet, to replace the one that was dissolved on Friday by the courts.
Analysts say Abbassi, a party loyalist, is unlikely to object to a short-lived stint in the top job, with this kind of horse-trading common in Pakistani politics.
"He'll step up to the plate. He's a politician's politician," said Ahsan Butt, an assistant professor at the Schar School of Policy and Government, George Mason University in Virginia.
"(He's a) reliable character as far as the PML-N is concerned," added Butt.
Just as Abbasi's elevation to the job was considered a foregone conclusion, so is the Punjab by-election.
It's a fairly safe PML-N seat so, barring any surprises, the younger Sharif is expected to coast to victory there.
"The PML-N is very strong in that region, they've controlled it even when they're not in control nationally," says Butt.
"It's a traditional party stronghold. One or two opposition parties will field candidates, but they'd be lambs to the slaughter."
Following the election, Parliament can confirm him as the new leader, with the US-educated Abbasi stepping aside.
As a sweetener, the short-term replacement could be offered another cabinet position, or his existing role -- until last week he was the minister of petroleum and natural resources.
He could even keep the portfolio during his brief tenure as Prime Minister, says Butt.
General elections, to be held next year, could then see the younger Sharif returned to power.
If he is re-elected and sees out a full term, he would be the first civilian prime minister in Pakistan ever to do so.
Six months ago, the obvious successor to Nawaz Sharif, who had ruled the country since 2013, was his daughter, Maryam Sharif.
But her elevation to power looks to have been scuppered by the corruption scandal that brought down her father.
The investigation focused on Sharif's alleged links to offshore accounts and overseas properties owned by three of his adult children. The assets, though not declared on his family's wealth statement, were revealed in the Panama Papers leak in April 2016.
The leak sparked mass protests in Pakistan and calls from opposition political groups for a panel to investigate Sharif and his children over their alleged offshore accounts, eventually bringing him down.
And the ongoing investigation into Maryam, her husband Safdar Awan, and her brothers Hassan and Hussain, is likely to extend past the deadline for nominations for next April's general election. They have denied any wrongdoing.
Analysts say her uncle, who will likely already be Prime Minister by then, will stand and, given the ongoing popularity of the PML-N, win the vote.
The Sharif name has already proven to be remarkably resilient.
The recently-deposed Sharif has served as prime minister twice before. He saw his first term end prematurely amid allegations of corruption, and his second end in a military coup which saw him jailed, then exiled, before returning to perform yet another political comeback.
Now it seems likely that his brother will keep the name relevant in Pakistan's power circles, and political analyst Butt says it would be foolish to rule out a comeback for Maryam at some point.
"I won't say (her political career is) dead in the water. In Pakistan politics, forever is a long time."