Spain ended their long wait for a World Cup knockout-stage goal as they eased through to the last 16 with a 3-0 win over Austria.Mikel Oyarzabal scored twice and Pedro Porro was also on target at Los Angeles Stadium, and Spain will now face Portugal or Croatia in the next round.Spain only completed 15 passes in the opening five minutes, their fewest in the first five minutes of a World Cup game since 2014.But Lamine Yamal, typically, had the contest's first chance, as he drilled a low effort at Alexander Schlager.Stefan Posch brilliantly blocked Dani Olmo's path in the box after some fabulous play from Yamal and Pedri, but Spain seemed to have made their breakthrough in the 29th minute.A corner from the right caused havoc for Austria's defence, with Marc Cucurella on hand to slam in, but referee Glenn Nyberg harshly decided Pau Cubarsi had fouled goalkeeper Schlager.Yamal forced another save when he took on a cross-shot from an impossible angle after some slick footwork on the byline, before Schlager kept out a crisp Oyarzabal strike.Yet there was nothing Schlager could do when Oyarzabal coolly side-footed home first time from Cucurella's low centre.Schlager pulled off a fantastic double save before half-time, keeping out Alex Baena's free-kick before thwarting Yamal on the rebound.Sasa Kalajdzic scored the goal to send Austria into the knockouts, and he almost equalised just moments after coming on as a 60th-minute substitute, but the striker could not keep his header down.Austria were made to pay for that miss in the 66th minute. Cucurella managed to force the ball into Baena, who supplied a drilled, left-footed cross into the centre of the area, where Porro met it with a superb header.Cucurella and Oyarzabal linked up again in the 89th minute, with the latter once again turning in from an inch-perfect cross to cap a superb Spain performance.La Roja end knockout-stage droughtSpain came into the World Cup as the Opta supercomputer's favourites, though Luis de la Fuente's team did not truly click into gear in the group stage.France and Argentina were fancied more by Opta's predictive model heading into the round of 32, but this was a confident, dominant display from Spain, who have shown what they are capable of, albeit against a disappointingly blunt Austria.Their dominance was reflected by tallying up 23 shots, 2.84 expected goals and 51 touches in the opposition box. In contrast, Austria did not even have a shot on target.Spain are now unbeaten in their last six meetings with Austria, but they had to end a winless streak in World Cup knockout-stage matches that stretched all the way back to the 2010 final, when La Roja beat the Netherlands 1-0 after extra time.In fact, Oyarzabal's opener was Spain's first World Cup knockout goal since Andres Iniesta's decisive effort in South Africa 16 years ago.That opened the floodgates, though, and when Porro doubled Spain's advantage, it marked the first time La Roja had netted multiple goals in a World Cup knockout match since they beat Switzerland 3-0 on July 2, 1994, exactly 32 years ago.Oyarzabal's second goal made him the first Spain player to score twice in a World Cup knockout fixture since Emilio Butragueno netted four against Denmark in 1986.The Real Sociedad forward has now netted 17 goals in his last 16 Spain starts, while Baena became the first Spain player to create five chances in a World Cup knockout match since Xavi in the 2010 final (also five).Yamal did not score, seeing a strike blocked off the line by David Alaba late on, but the Barcelona superstar dazzled. He has won all nine of the games he has started in major tournaments, and became the first player at this year's World Cup with 10+ dribbles (10) and 10+ touches in the opposition box (14) in a match. At 18 years and 354 days, he is the youngest player on record to do both.Yet Spain are also built on solid foundations. They are the first European team to keep a clean sheet in their first four matches at a World Cup since Switzerland in 2006, while Unai Simon has now kept a clean sheet in five consecutive World Cup starts, the joint-longest run by a goalkeeper in the competition, along with Italy's Walter Zenga in 1990.