Less than a day after helping Michael Phelps make Olympic history, Ryan Lochte laid the groundwork for another run at his illustrious team-mate as part of an ambitious backstroke-medley double. Lochte, who left Phelps in his wake in a dominant 400m medley victory to open the Games, stayed on course for another medley duel with defending champion Phelps as he posted the second-fastest time of the heats behind Hungarian Laszlo Cseh on Wednesday. Lochte also launched his defence of the 200m backstroke title he won in Beijing, settling for the second-quickest time of the morning heats behind team-mate Tyler Clary. The tough double follows on the heels of America\'s 4x200m freestyle relay triumph, which gave Phelps a record-breaking 19th Olympic medal. \"Last night, I used a lot of energy and there was some celebrating, which takes it out of you, so it is kind of hard to step it up in the morning,\" admitted Lochte, who led-off the relay squad. \"Especially doing two races back to back, but that is what I have been training for. \"This morning\'s races were easy, I just had to get a lane for tonight.\" While Lochte was cruising through his busy day, Australian James Magnussen was facing a pressure-packed men\'s 100m freestyle final. Magnussen admitted Australia\'s shocking failure to win a medal in the 4x100m free relay had dented his confidence, but he appeared to have his swagger back after leading the way into the final of the prestige sprint. \"It is quite an open field in the 100m, if I can get myself back to the sort of form I had at the trials, I have a good chance of winning it,\" said Magnussen, bidding to become the first Australian man to win the 100m freestyle Olympic gold since Michael Wenden in 1968. Other finals due Wednesday include the women\'s 4X200m freestyle relay and 200m butterfly, with top qualifier Kathleen Hersey of the United States trying to prevent world champion Jiao Liuyang of China from improving on the silver medal she won in Beijing. In the men\'s 200m breaststroke final, Japan\'s Kosuke Kitajima faces an uphill battle in his bid for a third straight title. No man has won the same swimming event at three straight Games, and Kitajima will be up against it in a field led by Hungarian world champion Daniel Gyurta and Britain\'s Michael Jamieson. Meanwhile Lochte said he he was pleased to have play a role in Phelps\' latest record-breaking feat during the relay. \"He is one of the greatest and he will go down as one of the greatest,\" said Lochte, who will nevertheless do his utmost do deny Phelps a third straight 200m medley gold. The duel between the two has top billing Stateside, but Hungarian Laszlo Cseh threatens to be in the hunt after taking silver behind Phelps and ahead of Lochte in Beijing. Cseh bounced back after what he called a \"terrible\" 200m butterfly, in which he failed to make the final. \"That was much better,\" he said. Chad le Clos, who out-touched Phelps for the 200m butterfly gold to hand the American his first major international defeat in the event in more than a a decade, also made it into the 200m medley semis. \"I was surprised at my time this morning, I didn\'t know if I was going to make it,\" admitted le Clos, who didn\'t get much sleep after his emotional win over his swimming hero. \"I have already watched the race about 10 times, my friends were waiting for me when I got back to the room and we watched it a few times. \"It was really awesome, really emotional,\" le Clos said.