The Romanian international fired home a stunning leveller in stoppage time as Barry Ferguson’s side came back from 2-0 down at Pittodrie with ten men.
Ross McCausland saw red in the first half, with the hosts going in at half-time with a two-goal lead.
But Hamza Igamane’s finish and Hagi’s strike saw the Light Blues return home with a share of the spoils.
Speaking to RangersTV, he said: “We are making it hard for ourselves this season.
“Coming back with ten men says a lot, but it is not the scenario we wanted, we wanted to come here and win.
“We have to take the positives, especially after playing so long in the last two games with ten men.
“We have managed to get results in tough circumstances. We have shown character and players are sacrificing for the team, but we need to do it consistently.
“The full focus is on Thursday now and we have to give something back to the fans.
“We can still win that competition, we have done well in it these last few seasons.
“We know it won’t be easy, but hopefully we can come out on top.”
Hagi was a second half substitute as Ferguson’s men fought their way back into the contest.
Cyriel Dessers thought he had netted to make it all square, only for his shot to cannon off the post, with Jefte then setting up Hagi for the equaliser.
The playmaker was delighted with his strike and hopes there are more to come between now and the end of the season.
He added: “The gaffer told me to try and get us back into the game. We changed the formation after about ten minutes after I came on to try and get the second goal.
“We did everything we could, it is positive we came back with ten men but it is not enough.
“I trust my strike on either foot, I would have preferred Cyriel to score, but he was unlucky.
“Jefte was switched on for the rebound to set me up and I am happy it went in and hopefully there will be more of that.”