Brendan Rodgers said he is facing the biggest test of his Celtic tenure after the Scottish champions suffered defeat at Kilmarnock.

Defender Stuart Findlay's last-gasp header handed Killie victory, and consigned the Hoops to their worst start in 20 top-flight seasons.

Domestically, Rodgers' stint in charge at Parkhead has drew nothing but success, with Celtic achieving the Double Treble across the Northern Irishman's two full seasons in the hotseat.

But a sluggish start this time out has seen the Hoops let eight points slip in six matches, the same total they dropped across the whole of the Invincibles campaign of 2016/17.

Asked if he was facing the biggest challenge of his time as Celtic boss, Rodgers said: "It is. It's a challenge.

"We have to accept that. There's no doubt we need to be better. When you're at the biggest clubs and you don't win the heat comes on to you.

"That's when you show you're a Celtic player, manager, member of staff.

"You come together. When you lose games the spotlight will always be on you.

"You have to work hard, do the basics right. The basics cost us this time.

"It hasn't been great, but we have to accept that. We're the only ones who can make it better and get more consistent results."

Defeats at Tynecastle and Rugby Park, plus a stalemate against St Mirren leave the Hoops currently five points off the pace.

Rodgers feels opponents are improving, while also having a "new-found respect" for his side.

He added: "The teams are playing deep. At St Mirren we saw it, even when we had 10 men. You saw Rangers come and sit deep, Kilmarnock did that too.

"It's up to us, we have to find the answers to that. That's the job.

"We have to analyse the game and build the mentality again to win your next game.

"I'd have been disappointed to draw, but to lose is bitterly disappointing. It was a scrappy sort of game, but I still feel we had the better moments and more control."

Steve Clarke has now guided Kilmarnock to two wins and two draws against champions Celtic.

The Killie boss praised former Parkhead youth player Findlay for playing through the pain barrier to score the winner.

He said: "I was pleased for Stuart Findlay. He didn't train all week, but he put his body on the line.

"He was struggling at half-time but those are some of the rewards the footballing Gods give you.

"Stuart had a bang on the knee and it was sore through the week. He got another bang in the first half but we've got good character in the squad.

"We were competitive. I was a little bit disappointed to be down at half-time because I didn't think we deserved to be after we started really well.

"We had decent control. Two mistakes on ball into box cost us, but we reacted well.

"We spoke at half-time about believing. We've shown we can compete with the big teams. Second half we competed well and deserved to get back in."