Giovani dos Santos scored twice as Racing Santander took a giant step towards Primera Division survival with a hard-fought win at second-bottom Hercules.
All five goals came in a frantic first 45 minutes of a hugely entertaining match, with Hercules' Paraguay forward Nelson Haedo Valdez sent off after an hour for an alleged elbow on Domingo Cisma.
Giovani had headed Racing in front after 13 minutes and later restored his side's lead moments after Sendoa Agirre's leveller with half-time approaching.
But there was still time for two more goals before the break as Tiago Gomes equalised with a deflected strike to make it 2-2 and Henrique headed home in first-half stoppage time after Juan Calatayud had come rushing off his line.
The second half was understandably a tighter affair, but Racing looked the better side - especially after the harsh dismissal of Valdez.
Substitute Julian Luque missed a great chance to make it 4-2 to the visitors when he hit the post with eight minutes left, but David Trezeguet was also guilty of a poor miss at the other end that would have given Hercules some hope of avoiding the drop.
As things stand, the Alicante-based side are still in 19th spot, six points adrift of 17th-placed Deportivo La Coruna - who drew 2-2 at Sporting Gijon - and with only three games left.
Racing, meanwhile, climbed to 11th place in the table and the Cantabrians look all but safe on 43 points.