Soon after trends for various Lok Sabha results came in indicating BJP's triumph, Advani talked to Modi over telephone and congratulated him.
The two leaders spoke for sometime and shared the good news of the party's impending victory, party sources said.
Advani, who was initially not happy over Modi being declared the party's Prime Ministerial candidate in September last, has been predicting the party's best-ever performance in these Lok Sabha polls.
He had also stated that the response of people towards BJP this time has been "unprecedented".
Advani had skipped the party's all-important meeting of the Parliamentary Board on September 13 last year when Modi was anointed the PM candidate.
He had also skipped the meeting of BJP's Executive Committee in Goa where Modi was anointed to lead the party's Campaign Committee in June last year, after which he resigned from all party positions in protest. He withdrew his resignation the next day following intervention from RSS leaders.
Meanwhile, top BJP leaders have been holding hectic parleys among them and with RSS top brass to decide on Advani's role in the next government led by it.
BJP President Rajnath Singh also congratulated Modi over telephone.