Lionel Messi's third goal from a free-kick in as many games this year secured Barcelona's place in the quarter-finals of the Copa del Rey as the holders beat Athletic Bilbao 3-1 to edge through 4-3 on aggregate on Wednesday.

Luis Suarez's 100th Barca goal and Neymar's penalty cancelled out Athletic's 2-1 first leg lead, but Enric Saborit's header six minutes into the second-half had the tie headed for extra time.

However, just as in the first leg and in a 1-1 draw at Villarreal on Sunday, Messi rode to Barca's rescue with another exquisite free-kick that clipped the inside of the post on its way past Gorka Iraizoz.

"There is a reason why Messi is the best in the world," Suarez told Barca TV. "He surprises you with something beautiful in every game."

Barca were under huge pressure to deliver their first win of the year as the slip-up at Villarreal left them five points adrift of Real Madrid at the top of La Liga, who also have a game in hand.

"It is important for our confidence. We wanted and needed a result like that," added Suarez. "We are calm, working hard and know that the results will come."

The build-up to the game had been dominated by talk of controversial refereeing calls in the first leg as Athletic ended the game with nine men, whilst Barca had a stonewall penalty claim waived away.

And there was more controversy on 26 minutes when Neymar was wrongly flagged offside as he set up Suarez for a tap in.

However, the same combination wasn't to be denied 10 minutes before half-time when Neymar's cross was hammered into the far corner by Suarez to bring up his Barca century.

"The important thing is it contributed to us going through, which is what we wanted," said Suarez.

The former Liverpool man's strike was also the 300th goal scored by Barca's fearsome "MSN" forward line since he joined the club in 2014 with Messi netting 124 and Neymar 76.

It was 301 just three minutes into the second-half when Neymar was chopped down by Eneko Boveda.

Messi handed Neymar responsibility from the spot and the Brazilian ended a 1,023-minute drought for Barca as he sent Iraizoz the wrong way to register his first goal since October 19.

Barca's joy was short-lived, though, as with their first serious attack Athletic got the away goal they needed when Saborit's downward header at the back post beat both Jasper Cillessen and Samuel Umtiti on the line.

However, Messi proved the match winner 11 minutes from time as he outfoxed Iraizoz. A week after beating the Athletic 'keeper to his right, the five-time World Player of the Year pulled his free-kick in off Iraizoz's left-hand post for his 26th goal in 23 games this season.

An incredible individual run by Neymar nearly sealed the tie as he hit the outside of the post moments later, but Barca held on to maintain their record of not being eliminated by anyone other than Real Madrid since 2008.

"I am very satisfied," said Barca boss Luis Enrique. "We controlled the game at every moment."

Barcelona will be joined by Real Sociedad, Alcorcon and Alaves in Friday's draw after they also secured their place in the last eight on Wednesday.

Atletico Madrid moved into the last eight on Tuesday 4-3 on aggregate despite losing 3-2 at home to Las Palmas.

Real Madrid carry a comfortable 3-0 lead into the second leg of their tie away at Sevilla on Thursday.