England were heavy favourites heading into their first Group D game against World Cup debutantes Haiti, but the European champions struggled to really pose a major threat throughout the tie.
Georgia Stanway scored England's opening goal of the campaign in the first-half, converting a retaken penalty after having her first attempt saved by Haiti's goalkeeper.
Despite 11 shots on target and having 75 per cent of the possession, though, Haiti kept the Lionesses' front line quiet, with the Caribbean side having big chances of their own.
And with the game ticking into the final stages, England's goalkeeper and FIFA women's goalkeeper of the year Earps stepped up to keep her side's clean sheet intact and secure a vital opening victory.
Roseline Eloissaint had burst past Millie Bright and Lucy Bronze and had looked set to equalise, only for the Manchester United keeper's outstretched foot to deny her.
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"That was as good as a goal," former Lionesses star and talkSPORT commentator for the game Lianne Sanderson said live from Brisbane.
"I was waiting for the net to ripple, I had my head in my hands and Mary Earps just stepped up and I think to myself, 'What would I have done in that situation?', from a centre-forwards perspective and I'd have done everything Eloissaint did.
"Mary Earps pulled off a fantastic save, absolutely brilliant."
Despite Earps' heroics, Sanderson also noted the reaction of England boss Sarina Wiegman, who had a muted celebration when the final whistle went and England saw out their narrow lead.
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"We can see Sarina Wiegman in the vision, she looks quite shell shocked I would say," Sanderson added.
"She looks quite calm as she always does, but she looks quite shell shocked, probably surprised that this game is no where near as comfortable as she'd have liked."
Goalscorer Stanway hailed recognised the important of Earps' save after the game, too.
"I think a top keeper like that, saves like that keep us in the tournament," she said. "The most important thing is we got three points, so off to a good start."
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