The US lead 3-1/2 points to 2-1/2 after the fourball session at Muirfield Village Golf Club and the 20-year-old Spieth got an early taste of the tension of the team game with his match going down to the wire.
"It was obvious that the nerves were affecting me at the start. He came up to me, and said, 'I know you've got the nerves going but hey let's start playing some golf now'.
"He was extremely supportive and helpful in getting me going. I made a putt on six and then we were both rolling from there," said Spieth.
Spieth, the US Tour Rookie of the Year, made six birdies but he and Stricker were up against a determined African pairing with Zimbabwe's De Jonge, in particular, in brilliant form making eight birdies.
Els won the 17th hole with a birdie - his only of the round - to reduce the Americans' lead to just one hole going into the final hole and Stricker ensured the victory after a great up-and-down from the bunker.
"He took care of me at the end, and all in all... you hate to see somebody lose but I couldn't have been happier that he got that up and down," he said.
The 46-year-old Stricker, who captain Fred Couples clearly identified as a solid partner for his young pick, sensed early on that the occasion was affecting Spieth.
"It's always important to get off to a good start and I knew what kind of nerves Jordan was going to be dealing with.
"I was in a similar spot a few years ago, long time ago, but it's a tough situation, and I thought the pressure was on me to come out and play well and try to make things easy for him, knowing what he was going to be facing throughout the day," said Stricker.
"So it was good that we got off to a good start. I think the rain delay helped us both. I think it helped Jordan here kind of regroup a little bit and same with me.
"There were a lot of pressure shots coming down to the end, but we were able to prevail."
Spieth said it had been a remarkable feeling to represent his country for the first time.
"It's amazing. It's something that's hard to describe," he said.
"When they announce you from the United States of America and you realise that it's the Presidents Cup, and you're standing next to guys like Steve and the best players in the world, it's a feeling that gives me chills now just to talk about."