Barcelona's Luis Suarez celebrates after scoring during Wednesday's Copa del Rey round of 16 second leg match against Athletic Bilbao at Camp Nou. Barcelona won 3-1 and advanced 4-3 on aggregate. Manu Fernandez / Ap

Lionel Messi's third goal from a freekick in as many games this year secured Barcelona's place in the quarterfinals of the Spanish King's Cup as the holder beat Athletic Bilbao 3-1 to edge through 4-3 on aggregate on Wednesday.

Luis Suarez's 100th Barca goal and Neymar's penalty canceled 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 freekick 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 was under huge pressure to deliver its first win of the year as the slip-up at Villarreal left it five points back of Real Madrid at the top of La Liga.

"It is important for our confidence. We wanted and needed a result like that," added Suarez.

"We are calm, working hard, and we know the results will come."

The build-up to the game was dominated by talk of controversial officiating in the first leg as Athletic ended the game with nine men while Barca had a stonewall penalty claim waived away.

There was more controversy in the 26th minute 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 halftime 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 Uruguayan'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 Oct 19.

Barca's joy was shortlived, however, as with its first serious attack Athletic got the away goal it needed when Saborit's downward header at the back post beat both Jasper Cillessen and Samuel Umtiti on the line.

Messi provided 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 shot 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 its record of not being eliminated by anyone other than Real Madrid since 2008.

"Messi was decisive, as always," Barcelona coach Luis Enrique said.

"I hope he can stay with us for many more years because there is no one better than him.

"I am very satisfied. We controlled the game at every moment. Our team played well, we had the calm to create our scoring opportunities.

"We were patient. They scored with the only chance they had."

Barcelona will be joined by Real Sociedad, Alcorcon and Alaves in Friday's draw after it also secured its 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 carried a comfortable 3-0 lead into the second leg of its tie away at Sevilla on Thursday.

Suarezslams 'commonsense' contract talk

Barcelona striker Luis Suarez has hit back at comments by the club's CEO that the Catalan giant won't "go crazy" when negotiating a new contract for five-time World Player of the Year Lionel Messi.

Barca CEO Oscar Grau said on Wednesday a new deal for Messi, who has 18 months left on his current deal, was being negotiated with "common sense and discretion."

Suarez took umbrage.

"With Messi what you have to do is give him a new contract, not have common sense," the Uruguayan said after netting his 100th Barca goal in just 120 appearances in Wednesday's 3-1 win over Athletic Bilbao.

Despite posting a record turnover of $719 million last season, a series of expensive new contracts for the likes of Neymar and Suarez means Barcelona is close to overstepping the 70 percent limit of turnover spent on salaries imposed by UEFA's financial fair-play laws.

Barca captain Andres Iniesta also has just 18 months left to run on his contract.

"I don't know what the CEO said, but tell me one game in which Leo Messi hasn't been decisive," said Barca coach Luis Enrique.

"I don't know about numbers, I know about football. We all want to enjoy watching Messi here for many more years."

Agence France-Presse