Real Madrid captures La Liga title
Gonzalo Higuain smashed home a superb 16th-minute opener after Cristiano Ronaldo had earlier missed horribly from the penalty spot.
But the Portuguese recovered to beautifully create a second for Mesut Ozil in the 20th minute and got on the scoresheet himself five minutes after the break with a simple header from Ozil's corner, his 44th league goal of yet another prolific season.
The win kept Madrid seven points ahead of Barcelona with two games to go, Barca's 4-1 win over Malaga earlier this evening merely delaying the celebrations of a 32nd title by a matter of hours.
The success means Madrid coach Jose Mourinho has now won the league title in four different countries following his triumphs with Porto, Chelsea and Inter Milan,
Athletic, who perhaps had their minds on other things with Europa League and Copa Del Rey finals to look forward to, finished with 10 men following Javi Martinez's harsh sending off for two handballs.
Madrid and Ronaldo started brightly at San Mames, clearly eager to respond to Barca's win and Lionel Messi's hat-trick against Malaga.
Fabio Coentrao stung the palms of goalkeeper Gorka Iraizoz before the visitors were awarded a penalty.
Martinez was rightly penalised for handball, having raised his arms above his head when the ball struck them, but Ronaldo's spot-kick was woeful.
The forward, who missed from the spot in Madrid's penalty shootout defeat to Bayern Munich in the Champions League, tried to clip his effort down the middle, but it struck Iraizoz's legs and looped over the bar.
Mourinho's side did not have long to wait for the opener, though, as Higuain, starting ahead of Karim Benzema, controlled a pass from Ozil, shifted the ball on to his right foot and rifled a shot into the top corner from the edge of the area.
Ozil made it two four minutes later, Ronaldo picking him out at the back post with a superb low cross from the right which the Germany international slid back across goal inside the far post.
Markel Susaeta fired an effort against a post as Athletic threatened to get back into the game, but at the other end Ozil's long-range effort clipped the top of the bar.
The capital club moved further ahead in the 50th minute, getting a free run toward the six-yard line to head home the influential Ozil's corner.
It was Ronaldo's 44th league goal of the season, leaving him two behind Messi in the race for the 'Pichichi' after the Argentinian's treble on Wednesday.
Madrid continued to push for more goals, Jose Maria Callejon seeing a shot tipped round a post by the overworked Iraizoz.
Oscar De Marcos crashed a 25-yard effort off the bar for Athletic, but the hosts' misery continued when Martinez was shown a harsh second yellow card for another handball and sent off.
Ronaldo should have got his second in stoppage time when he raced clear of the last defender, but his finish was weak and Iraizoz made a comfortable save.
His disappointment did not last long, though, as the final whistle meant the celebrations could start for Madrid.
Information from The Associated Press was used in this report.