Pakistan's win at the MCG was their first in ODIs against Australia, in Australia, in over 12 years. Between this win and the previous one - at the WACA in 2004-05 - Pakistan had lost nine consecutive ODIs against the hosts. This was their longest-ever losing run against any host country in ODIs. Pakistan's next-worst losing sequences against host teams are their eight straight losses in West Indies, from 1977 to 1993, and in England from 1978 to 1987.
Australia have inflicted such streaks on other teams as well. Pakistan's nine-match losing streak wasn't the longest for a visiting team against the hosts in Australia. England lost 13 consecutive games against Australia from 1999 to 2007, matching a similarly-long losing streak for Sri Lanka from 1985 to 1995.
Bangladesh have the unwanted record of having lost the most consecutive ODIs to any host country: they lost 14 straight matches to Sri Lanka in Sri Lanka before winning their first one in Pallekele in 2013. There are 11 other sequences that have lasted for ten or more ODIs and Australia have been the hosts in four of these.
Pakistan's win at the MCG also ended their run of 16 consecutive losses across formats to Australia in Australia. Between their ODI win at the WACA in 2005 and their latest one, they had lost six Tests and one T20I in addition to the nine ODIs. The record for the worst losing-streak though belongs to Bangladesh, who lost 21 matches to host country Sri Lanka. They had lost 13 ODIs and eight Tests from 1986 to 2010 before they drew a Test match for the first time ever in Sri Lanka, in Galle in 2012-13.
Incidentally, Bangladesh are on the verge of ending another of their losing sequences: should they not lose the ongoing Test match in Wellington, they will end their run of 19 losses across formats in New Zealand - currently the second-longest run of losses across formats against any host team.