Joe Hart reckons Celtic were unlucky not to claim victory against "proper opposition" in Rangers.
Both sides passed up chances in a derby draw that leaves Ange Postecoglou 's side on the brink of reclaiming the Premiership title.
Jota gave the league leaders a first-half advantage before Fashion Sakala levelled after the interval.
Daizen Maeda was wasteful with a pair of opportunities and Sakala was denied by Hart and then the post as Rangers pushed for a winner.
But Hart reckons Celtic could've been out of sight before their rivals mounted a late push.
The Celtic keeper said: "They're a good team. Champions last year, semi-finalists in a top European competition.
"We're playing against proper opposition and we worked hard to make those chances.
"No, we didn't take them. On another day, we could've been more comfortable but ultimately we weren't.
"Tight game, tight game."
Celtic now need just four points to confirm their status as champions but a vastly superior goal difference means victory over Hearts next week will effectively put an end to the title race.
Hart ensured the gap to Giovanni van Bronckhorst's side remained at six with some impressive stops in the dying minutes but insisted there remains more work to do.
He said: "We've come through a lot, we're pleased with where we are. We've got a job to do and that continues.
"They were fighting for their lives out there. It was more important that they won today than we did.
"I was well aware that, with however many minutes to go, that I felt like we were going to get chances and they were probably going to get more.
"I think they hit the post after that.
"Tough game. Great game, really, really good game to be involved in."
