Great Britain women's captain Hollie Pearne-Webb felt it was a case of three points that got away following a 2-1 defeat against Germany at the Oi Hockey Stadium.
Champions at the Rio Olympics five years ago following a dramatic shoot-out victory over Holland when goalkeeper Maddie Hinch saved four penalties, Britain went ahead through Sarah Jones' early goal in their opening Pool A game.
But Rio bronze medallists Germany hit back to triumph through a penalty by Viktoria Huse and Charlotte Stapenhorst's third-quarter winner.
A thoroughly entertaining game but it's π©πͺ who emerge victorious@sarahjones8888 gave us the lead early on but goals from Huse & Stapenhorst hand their team the three points We return to action against πΏπ¦ at 10:30 on Monday 26 July π pic.twitter.com/np6PeRRwfa β Great Britain Hockey (@GBHockey) July 25, 2021
Britain and Germany players, meanwhile, took the knee ahead of the game, showing support in the fight against racism and social injustice.
"We are going to go back and look at the stats and I think it will show it was a really dominant performance," Pearn-Webb said.
"On the balance of play, the three points should have been ours. However, we didn't make it three points.
"They wouldn't have had many opportunities, and we had numerous corners, and that's the difference in hockey β both circles."
There are seven survivors from Rio in Britain's current squad, including Hinch and Pearne-Webb.
"We look back at Rio and what we did, but equally this is a very different squad with lots of new players and a new coach," she added.
"There was a danger with a very new group we could have come out here and been a bit nervous, but we started really confidently, had them on the back foot and momentum was in our favour.
"And now we are in the tournament, game one is out of the way, it's South Africa on Monday and we need to show the confidence and dominance we showed in this game."
Britain showed purpose and intent from the start, gaining three penalty corners in the first four minutes with Sarah Robertson prominent.
All square at the break. Sarah Jones gives #TeamGB the lead over Germany before a penalty stroke brings the match level. pic.twitter.com/wJXXcVnTFV β Team GB (@TeamGB) July 25, 2021
German goalkeeper Kira Horn was kept busy, but her team managed to weather a considerable early storm as Britain launched wave after wave of attack.
An opening quarter briefly held up following technical issues after Germany made a team video referral, continued with a fifth penalty corner and Britain opened their account.
Germany could not clear the ball and Wales international Jones was in the right place at the right time to strike from close range and give Britain a richly-deserved lead.
They could not maintain it, though, at the start of a campaign that also sees South Africa, Ireland, Holland and India in their group.
Great Britain's women taking the knee before this morning's match. Proud of them for showing their continued support in the fight against racism and social injustice. pic.twitter.com/B8UnnWb9ym β Great Britain Hockey (@GBHockey) July 25, 2021
Jones said: "There were just little moments in the game that we can definitely tighten up on for tomorrow, which can make all the difference.
"There are a lot of games, and it is all about building momentum and making small adjustments.
"I think it is an incredible legacy to have (from Rio), and I am so proud to be able to pull on that shirt knowing that the girls before us are reigning champions.
"But we are all about making our own history as a new team."