The victory sees the Reds move to within one point of top spot after Melbourne and Sydney FC both suffered defeats.
Cristiano netted in the 72nd minute with a header and then rounded off the scoring in the dying minutes thanks to a blunder from Jets keeper Ante Covic.
Reds coach Aurelio Vidmar was delighted with the result, especially considering the fact that many of his players may have been suffering fatigue or tiredness on the back of a cluttered two week schedule.
“They’ve gone through five games in 16 days and that’s a massive effort,” Vidmar said after the game.
“There was a bit of doubt in my mind tonight of how of how they were going to come up tonight and they were a bit flat but for the boys to go out tonight and really squeeze every last bit of energy they had in their bodies, it was a superb effort.
“It was extremely important that we take the three points tonight. Sure, we had a bit of luck with Newcastle’s injury but that’s the way it goes so it probably fell into our hands a little bit in the second half.”
Adelaide now sits third on the table with three wins and a draw from six matches whilst the Jets find themselves in sixth place with just the one win.
Both teams have home games next week, the Reds take on Central Coast on Friday night and the Jets meet Wellington on Sunday afternoon.