TOKYO, July 24 (Reuters) - World champions Belgium beat the Netherlands 3-1 in the men"s hockey tournament at the Tokyo Olympics on Saturday thanks to a stunning hat-trick from Alexander Hendrickx, while Germany and Britain also won their first group matches. The Dutch women"s team, who are favourites to win their competition, defeated India, lifted by two crucial goals from rookie midfielder Felice Albers, who made her Olympic debut. Hendrickx scored three goals in five minutes as the Belgians came back from a goal down to take revenge on the side that beat them in the EuroHockey semi-finals last month. "There, our product was not finished yet. Now, we"re already one step closer to that finished product," said Hendrickx, who scored a penalty stroke and from two penalty corners. "We played calm and kept the ball in the team. We killed the game." Germany thrashed Canada 7-1, with two goals each from explosive forward Jan Ruhr and defender Lukas Windfeder. Britain, who have won Olympic gold in the men"s tournament three times, defeated South Africa 3-1 helped by a second minute goal from Sam Ward and two more in the second half. "I think we performed well, we just didn’t take our chances," Ward said. Earlier on Saturday, Australia beat hosts Japan 5-3 in a thrilling opening match, while India recovered from a goal down to defeat New Zealand 3-2. DUTCH WIN In the women"s tournament, world and European champions the Netherlands beat India 5-1, helped by goals from Albers, 21, who is the youngest player on the Dutch side. She described her Olympic debut in the tree-ringed stadium as beautiful. "You can never predict how something like that will go, but I think it was a good match for an Olympic debut," Albers said. "My dream is coming true here and I think this is a good first step in the tournament." Ireland"s women"s team beat South Africa 2-0 at their first Olympics. In the men"s tournament, Australia"s "Kookaburras" trailed 3-2 at halftime against Japan after conceding three goals in quick succession but kept fighting to turn the tables in the final two quarters. "Luckily, we got the three points and we"re just looking to build each and every game," said midfielder Daniel Beale, who scored the final goal. "This is definitely a good place to start with a win." The Australians pulled level in the 34th minute after Blake Govers scored a penalty corner and went ahead on the sun-drenched pitch of the main stadium with a backhand shot from captain Aran Zalewski that flew high in the net. Beale took an assist from forward Tim Brand to put the game away. Australia"s players were taking on plenty of ice water and using fans and cold towels to cool themselves during breaks but Beale said they would adapt to the humid conditions. "It"s hot, but we"re just going to deal with it and get on with it," he said. "Luckily coming from Australia we"re used to a high heat so I think everyone has to deal with it. The team that copes the best is going to go the furthest in this tournament." Rio gold medallists Argentina drew 1-1 with Spain after conceding in the 52nd minute while playing with a man down following a yellow card minutes earlier. India, who have won gold medals at eight Olympics, conceded early against New Zealand but equalised quickly through a penalty stroke and roared on to win, with two goals from Harmanpreet Singh and one from Rupinder Pal Singh.