0134 GMT March 24, 2018
Shahbaz was elected unopposed as no one filed nomination papers against him during a rowdy party meeting held in the capital Islamabad on Tuesday.
Shahbaz told a roaring crowd chanting party slogans that he could not even think of replacing his brother. "Nobody including me can imagine taking the place of Nawaz Sharif."
In late February, the party cleared the way for Shahbaz's promotion to head the Pakistan Muslim League-Nawaz (PML-N) following Nawaz’s latest disqualification by the Supreme Court.
In the court order, Chief Justice Mian Saqib Nisar on February 21 directed the Election Commission of Pakistan to remove Sharif as head of the PML-N from all relevant records. The decision by the country's top court effectively bared Sharif from leading the PML-N.
Nawaz resigned in July after the court ousted him from office for concealing financial assets. Nawaz could end up in jail if he is convicted in a separate corruption trial expected to take place soon.
Sharif was the 15th prime minister in Pakistan's 70-year history to be ousted before completing a full term. Sharif has served as prime minister twice before and each time was removed from office, in 1999 by a military coup and 1993 by presidential order.
The Sharif clan and their supporters have repeatedly denied allegations of corruption, suggesting the three-time premier is the victim of a conspiracy driven by Pakistan's powerful military establishment. In recent weeks, Nawaz and his daughter Maryam have waged a war of words against the judiciary and military.
The move to elevate Shahbaz in rank has been seen as an attempt to continue the dynastic political system, which has been opposed by critics.
Shahbaz, 66, is currently serving as the chief minister in Punjab province. He has built a reputation as a competent administrator who gets things done, especially mega projects that are the cornerstone of the party’s electoral appeal.
His election is likely to prompt speculations that he will replace Shahid Khaqan Abbasi as prime minister if the party sweeps back to power after general elections due in the summer.
Shahbaz however faces steep challenges after the party's candidate lost in the race to lead the upper house of parliament on Monday following an unlikely alliance forged by the opposition Pakistan Tehreek-e-Insaf (PTI) and the Pakistan People's Party (PPP).The debacle at the Senate was the latest blow to the PML-N and its leaders.