In day two in the women's competition, the group stages began to take a little bit of shape with another 24 goals netted in six games.
In Pool B, Argentina dropped points for the second game in a row, to keep all six teams in the hunt for a semi-final berth, letting slip a 2-0 half-time lead against Britain.
Soledad Garcia and Alejandra Gulla's deflection gave one of the pre-tournament favourites the advantage but the game turned when a Mariana Gonzalez Oliva was shown the yellow card.
Welsh woman, Sarah 'vagabond' Thomas, scored a neat aerial tap-in and Mel Clewlow spanked in a penalty corner two minutes later which Mel Clewlow to get back on terms early in the second half. The South Americans looked more dangerous but final passes went astray to give them two draws from two.
Germany look well placed to advance as the only team in Pool B with full points. The came from a goal behind to beat New Zealand 2-1. Against the run of play, Krystal Forgesson smashed a loose ball off a saved penalty corner into the roof of the net.
Katharina Scholz slammed the ball home off a long hit into the circle, finishing off a quick break with the elusive equaliser with just 11 minutes left. The Germans suffered through a prolonged video umpire decision, but the goal stood.
And Anke Kuehn snatched the points in the last minute, flicking into the net, to add to their 5-1 win over GB.
Elsewhere, the USA got their second draw, tying 1-1 with Japan to leave the Pool B table after two games (points/goal diff): 1. Germany (6, +5) 2. Japan (4, +1) 3. Argentina (2, 0) 4. USA (2, 0) 5. Great Britain (1, -4) 6. New Zealand (0, -2)
Pool A is much more clear-cut with three sides on maximum points and three yet to get on the board.
Australia had a much easier task than their battle with Korea, but were still made to work for their 6-1 win over Spain. After a slew of Hockeyroo chances, Spain shocked the crowd when Silvia Muñoz slapped in a rebound off a Maria Romagosa hit.
The Spaniards held out for 20 minutes before levelling through Angie Lambert - Australia's 100th Olympic goal, becmong the first women's team to reach that milestone.
A fading Spanish team hit the wall midway through the second half, as a fabulous solo goal from Nikki Hudson broke their resistance. Casey Eastham, Emily Halliday, Megan Rivers and Lambert added further strikes on the home stretch.
For the second game running, the Koreans were on the wrong end of a thriller and look to have little chance of progressing despite some hugely impressive play. They lost 3-2 to the Netherlands in a hard-fought, fast-paced game.
Both teams were off to a cracking start, with three goals scored in the first seven minutes of the game. The tournament's top-scorer to date, Maartje Paumen, opened the scoring in the third minute from a penalty corner, but Korean captain Seon Ok Lee responded within a minute.
A further Dutch corner was converted by Janneke Schopman as both sides played at full tilt. The impressive Koreans levelled from the penalty spot but their hearts were broken for the second game running when Paumen nailed a hotly contested corner to end the game 3-2.
The Dutch have a key match on Thursday against the third unbeaten side, China. The hosts won 3-0 for the second game in succession, taking the lead early from a Chunling Tang goal, deflecting a Ma Yibo hit.
China were much superior and a brilliant Fu Baorong and Qingling Song's reverse sealed the win.
Pool B: 1. Netherlands (6, +7) 2. Australia (6, +6) 3. China (6, +6), 4. Korea (0, -2), 5. Spain (0, -8), 6. South Africa (0, -9)