A Cristiano Ronaldo hat-trick, the 51st of his illustrious career, included a first goal from a direct free kick at a major international tournament and saw Fernando Santos' side snatch a point in the final few minutes in Sochi.
Continuing to defy his advancing years, Ronaldo became just the fourth man in history to score goals at four different editions of the World Cup and has elevated himself to pole position in the top scorer race.
The Real Madrid frontman was cut from 14/1 (15.0) pre-match to 7/4 (2.75) favourite to be the Golden Boot winner in dabblebet's latest World Cup odds. The European champions will now face Iran and Morocco in their other Group B encounters.
La Roja had leaked just three goals in qualification for Russia 2018 but conceded as many in 90 minutes thanks to Ronaldo's brilliance.
While David De Gea's performance was a world away from what Manchester United fans have come to expect, Fernando Hierro's side showed their attacking prowess in spades and looked consistently dangerous in the final third.
Costa was substituted in the second half but has surely cemented the starting position which had been in question before the action got underway.
Spain are now 5/1 (6.0) to go all the way after picking up a share of the spoils while Portugal are 25/1 (26.0) to repeat their Euro 2016 triumph. Brazil remain favourites at 4/1 (5.0) ahead of their first match while Germany are 5/1 (6.0) to defend their title.