The coadjutor of the diocese, Bishop Michael Yeung Ming-cheung, and vicar general, Father Dominic Chan Chi-ming, gathered to extend their congratulations to Lam, who is a parishioner at Our Lady of Mount Carmel in Wan Chai.
Although widely believed to be the preferred candidate of Beijing, Lam is far from being the favourite of the people in the street, running a distant second to her main rival, John Tsang Chun-wah, in popularity rating surveys taken in the run up to the March 26 day of reckoning.
She provoked a strong response from Cardinal Tong when she included the possibility of setting up a government Religious Affairs Unit in the special administrative region in her election manifesto, which culminated in the bishop of Hong Kong writing to her to express his opinion that he did not think it was a good idea.
The cardinal also encouraged her strongly to work to establish a robust democracy in the city during her term.
Lam later backed down on the idea, leaving many in the Church wondering if she really understood the implications of what she was suggesting
Cardinal Tong congratulated Lam on her victory and wished her well in serving the people of China and Hong Kong when she formally takes office on the 20th anniversary of the return of the former British colony to Chinese sovereignty on July 1.
In her turn, Lam thanked Cardinal Tong for his support and encouragement, adding that she has always tried to be guided by Church teaching.
Lam was educated by the Canossian Sisters and said that she has always taken her school motto, Live by the truth in love, as a guiding light in her life.