Women's Rugby World Cup - Pool C
New Zealand (21) 54
Tries: Miller 2, Mikaele-Tu'u, Leti-I'iga 2, Ponsonby, Woodman-Wickliffe, Setefano Cons: Holmes 7
Spain (3) 8
Tries: Antolinez Pen: Argudo
Defending champions New Zealand started their quest for a record-extending seventh Women's Rugby World Cup with a curious 54-8 win over Spain at York Community Stadium.
Seeking to show their credentials after title rivals England and Canada compiled big wins in their opening matches, the Black Ferns only led 21-3 at half-time as Spain produced a battling display that belied their world ranking of 13.
Overcoming their first-half rustiness, New Zealand ran in five tries after the break, despite having to play with 13 women for the final 17 minutes.
Head coach Allan Bunting had already used all his replacements when Kaipo Olsen-Baker went off on a stretcher on 55 minutes following an injury to her right leg.
New Zealand were reduced to 13 when wing Ayesha Leti-I'iga also had to go off because of injury.
The Black Ferns still managed to score a try despite their two-player disadvantage but they conceded in the final play of the game as Spain touched down for a score their efforts deserved.
Jorja Miller caught the eye in the first half, scoring two first-half tries in a dazzling 40-minute World Cup debut before being replaced.
The great Portia Woodman-Wickliffe, who came out of international retirement in April in a bid to win a third successive World Cup, scored her 21st World Cup try as New Zealand found their form in the second half.
Miller stars in first half
Miller, the World Sevens player of the year, gave New Zealand the lead in the 13th minute with a try that demonstrated why she is tipped to be a superstar of the game.
The 21-year-old flanker threw a dummy, stepped inside two defenders and accelerated through what was left of Spain's defence.
The Olympic sevens gold medallist, who only played her first 15-a-side Test in May, got her second three minutes later, touching down on the right-hand side following a fluent passing move.
Miller, sensing the chance for a spectacular hat-trick, went off on another rampaging run straight from the restart but this time Spain managed to bring her down.
She beat 11 defenders in the 40 minutes she played, the most of any player in all eight of the matches on the opening weekend of the World Cup.
Number eight Liana Mikaele-Tu'u, who was also outstanding, powered over her defender to bring up the champions' third try but they then needed to defend well to keep the Spanish side at bay.
Las Leonas, beaten 97-7 by England in a warm-up match, deservedly got points on the board with a penalty from Amalia Argudo and, roared on by the York crowd, continued to make life uncomfortable for the Black Ferns.
The second half was a different story with left wing Leti-I'iga going over for New Zealand's bonus-point fourth try shortly after the restart.
Replacement hooker Georgia Ponsonby motored over from a maul and then Leti-l'iga used all her formidable strength to resist two tackles and touch down in the corner for her second try.
Down to 14, Woodman-Wickliffe, the tournament's all-time record try-scorer, ran a great line to go over for her score, and then with only 13 players on the pitch centre Theresa Setefano broke through to score under the posts.
Spain did not give up and got their reward in overtime with a try from Ines Antolinez, which sparked jubilant scenes among the exhausted Spanish players.
New Zealand take on Japan in their second Pool C match in Exeter next Sunday, while Spain face Ireland on the same day in Northampton.
The Black Ferns' match against Ireland on 7 September is expected to determine who wins the pool.
Line-ups
New Zealand: Holmes; Sorensen-McGee, Du Plessis, Setefano, Leti-I'iga; Brazier, Hohaia; Tangen-Wainohu, Green, Rule, A Bremner (capt), C Bremner, Sae, Miller, Mikaele-Tu'u
Replacements: Ponsonby, Viliko, Kalounivale, Bayfield, Olsen-Baker, Pouri-Lane, Demant, Woodman
Spain: Ducher; Bueriberi, Pena, Perez, Piquero; Argudo, Fernandez de Corres; Delgado (capt), Blanco, Bracic, Castelo, Alameda, Martinez, Garcia, Capell
Replacements: Jou, Antolinez, De Andres, Puig, Pineiro, Aresti, Vinuesa, Perez
Officials
Referee: Ella Goldsmith (Australia)
Assistant referees: Kat Roche (USA) and Amber Stamp-Dunstan (Wales)
Television match official: Quinton Immelman (South Africa)