Reed and his men’s four team-mates picked off rivals Australia to finish first in 5:58.26 minutes, as they were roared on by a loud home crowd.
Reed insists that his boat of Tom James, Andrew Triggs-Hodge and Alex Gregory are in the right form to complete the job, and is enjoying the responsibility of being the tactician.
“We have another gear,” said Reed, who will now look to claim a second gold in the men’s four.
“We were rowing better in the first 1,000 (metres) than in our heats, and then it was just job done. Then it was maintaining what we had to do and limiting our efficiency.
"In that race, there was lots of pressure, but I felt alive on the start, ready and buzzing. Whatever the Australians do, we can do as well. I don't think we've seen the best from Hodgey or TJ, and my engine is phenomenal at the moment.
"I only need to say one word to the crew for them to go. It's my job as tactician and leader of the boat that it comes at the right time, and our gear changes come at the right time.”
Reed, a serving lieutenant in the Royal Navy, thanked the crowd for their efforts and believes they really act as an extra man in the boat.
He said: “We've heard them on the start, and we've seen enough racing so far to know that when the cameras are on the British boat you can hear a roar. We felt that from the start.
"I was just sitting up and felt enormous pressure. I felt alive. Coming into the last 500m is where the crowd makes a difference.
"Coming into the last 250m, you can't slow down when the crowd are shouting because the other crews know they are shouting for us and not them. So thank you to the crowd for supporting us so well."
Katherine Copeland and Sophie Hosking stormed into the final of the women’s lightweight double scull, beating world champions Greece, who finished second.
The pair crossed the line in clear water in a time of 7:05.90 mins and Hosking says the focus is now straight on the final on Saturday.
She said: “There’s a job to be done. We talk a lot about being calm and having intensity in what we do when we race, but we’ve got to have the utmost desire in our boat, but we’ve got to be calm in that.
“Things will be going on around us, but we have to be fully committed to what we’re doing and I think we showed that today – our confidence is growing.”
Defending champions in the men’s lightweight double scull pair Zac Purchase and Mark Hunter saw themselves through to a second successive final in 6:36.62 mins.
However, despite looking comfortable for much of the race, Purchase and Hunter needed a strong last 100m to ensure they beat their French rivals.
Hunter admitted that he and Purchase have a lot to do when it comes to the final, but promised all will be done to win that gold medal.
“We will raise our game for the final,” said Hunter.
“Today wasn't our best row but it was quite challenging and we had to win the race to get a good lane in the final – I am confident.
“We've had two good races together, beaten two great crews and put ourselves in a really good position for Saturday."
In the men’s double sculls pair, Bill Lucas and Sam Townsend gave their all but could only finish in fifth place, despite a fantastic start.
Lucas and Townsend were in a bronze medal position at the halfway stage, but tired over the last 750m, eventually finishing in a time of 6:40.54 mins.
Meanwhile, the women’s eight finished in fifth place in their final in a time of 6:18.77 mins, behind the experienced USA crew – the current world champions – who won in 6:10.59 mins.