"It's quite a nice feeling when you hear that cheer and support, it gives you a lift."
The decisive moment came in the seventh game of the final set. At 3-3, Erakovic broke Puig to love with a series of unreturnable shots and was good enough to serve out the match three games later.
She will now line up against Czech Barbora Zahlavova Strycova in the final match of tomorrow's day session.
Earlier, top seed Caroline Wozniacki had no problems in her first singles appearance, clinically accounting for Israeli qualifier Julia Glushko in straight sets.
The world No 8 looked every bit the tournament favourite as she outclassed her rival 6-3 6-2 in front of a packed centre court crowd.
The 24-year-old Dane now eyes a second round appointment with American wildcard Taylor Townsend, who impressed in her victory over former title holder Yanina Wickmayer yesterday.
Wozniacki enhanced her status as one of the fan favourites by blowing kisses to the fans and taking time to hit balls into the stands, with Neil Diamond's 'Sweet Caroline' filling the airwaves.
In the late afternoon match, Venus Williams cruised into the second round after demolishing Jana Cepelova in 52 minutes.
Williams was barely tested - her opponent seemed overawed - but still showed plenty of touches of quality. She sent down ten aces, dropped only three points when her first serve landed and broke Cepelova on five occasions.
It's early days but positive signs for Williams, who has already signalled her intention to go one better than her runner-up result at last year's tournament.
The American will face Japan's Kurumi Nara in tomorrow's second round. The two have only met on one previous occasion, with Williams winning in straight sets last year at Wimbledon.
Yet another seed fell on centre court earlier in the day, continuing the run of upsets at the Auckland tournament.
Former world No2 Svetlana Kuznetsova has been beaten by Czech qualifier Lucie Hradecka 3-6 7-6 (8-6) 6-4 in a match lasting almost two and a half hours.
Hradecka was good value for the win, overcoming a bright start by Kuznetsova to record the second win by a qualifier today.
The 153-ranked Czech will face popular Auckland visitor Julia Goerges in the second round.
Meanwhile, 2009 ASB Classic finalist Elena Vesnina also progressed to the next round, beating France's Kristina Mladenovic 7-6 6-2.
Polish qualifier Urzula Radwanska also continued the upset trend, beating former Grand Slam champion Francesca Schiavone in straight sets.
Sure, Schiavone is not the same player who took the 2010 French Open but the Italian was still ranked almost 100 places higher than her opponent.
However she was outplayed for most of the match and lost 6-4 7-5 to Radwanska, who was playing her fourth match in four days.
Radwanska's lowly ranking (179) is a bit deceiving; the 24-year-old has been ranked as high as 29 in the world but has been dogged by injury in recent years.
Radwanksa sprinted to a 5-0 lead in the first set and despite a Schiavone mini-comeback was good enough to close it out. The 34-year-old Schiavone improved in the second set but was still plagued by errors and Radwanksa took the match on her second match point.
In other first round matches on Tuesday popular German Julia Goerges prevailed over another qualifier Anna Tatishvili 6-1 6-4 while young American Coco Vandeweghe beat Italian Roberta Vinci in three tough sets 5-7 6-2 6-3.
