Alisson made an "unbelievable" late save to ensure Liverpool qualified for the Champions League knockout rounds, said Andy Robertson.

Brazil international goalkeeper Alisson brilliantly denied Arkadiusz Milik in the second minute of added time with Liverpool holding on to their 1-0 lead at home to Napoli on Tuesday.

A narrow victory means Jurgen Klopp's side, beaten finalists in last season's Champions League, qualified from Group C behind Paris Saint-Germain with Napoli dropping into the Europa League.

And for Robertson there was no doubt Alisson's stoppage-time impact was decisive as Liverpool kept a vital clean sheet to progress.

"We knew we had to get a fast start and that's what we did," Robertson said to BT Sport.

"At 0-0 they had nothing to lose and they threw up their centre-back. It was an unbelievable save from Alisson.

"But to get 1-0 up we were confident we would keep a clean sheet and thankfully that's what we did."

While Alisson protected Liverpool's 1-0 lead, they were indebted to matchwinner Mohamed Salah at the other end.

The forward scored a sensational solo goal, finishing superbly through the legs of David Ospina after beating two Napoli defenders for strength and pace.

Salah's ninth goal in nine home appearances for Liverpool in the Champions League proved enough to secure progression, with team-mate James Milner highlighting the Egypt star's impact.

"It was always going to be a tough game - they're a good team," Milner told BT Sport.

"I thought it was a really good performance, we knew we had to defend well and we defended really well from front to back.

"Mo's goal too... he's a matchwinner, a world-class player and he's done it for us again."