Chigumbura hit eight boundaries and a six in his 35-ball knock after Zimbabwe won the toss and decided to bat.
Opener Hamilton Masakadza scored 43 while Pakistan's recalled paceman Mohammad Sami took three wickets.
Pakistan had not hosted any international cricket since terrorists attacks on the Sri Lankan team bus in Lahore in 2009 forced international teams to refuse tours to Pakistan.
Strict security was put in place with 4,000 policemen on duty but that did not stop the cricket deprived fans to pack the 27,000 capacity stadium.
The second Twenty20 will be played on Sunday followed by three one-day internationals on May 26, 29 and 31 -- all in Lahore.