Dundee manager Paul Hartley says that Celtic have true title challengers this season after Aberdeen narrowed the gap at the top to only four points.
Hartley's side drew 0-0 with the Scottish Premiership leaders in Glasgow on Wednesday night and Hartley insists the league table backs up his belief.
"There is a title challenge," he told BBC Scotland. "Four points says that.
"They have still to play each other and anything can happen with 10 [league] games to go."
Hartley, who played for both clubs, says the season run-in should be intriguing, with every club having something to play for between now and May.
"Probably both teams at the top can't afford too many slip ups, but it's great for Scottish football," he said.
"Down at the bottom and in the middle, teams trying to get into the top six and get into Europe, teams trying to avoid relegation, the play-off, the top two going for the title.
"So it's going be an exciting end to the season, but there is definitely a title challenge going on."
Hartley takes his team to Ibrox to face Championship leaders Rangers on Saturday looking to book their place in the semi-finals of the Scottish Cup.
He insists his players will once again have to be at their best if they are to reach the last four.
"It's going to be close to a full house and it's [about] how the players handle that," he added.
"We will go there with a game plan. They will have to show bravery and we can't freeze on the occasion.
"We will help them as much as we can, but when they go there, they have to be brave and trust each other."