Spieth earned one of the most prestigious honors for amateurs by shooting 69-70 on the weekend. He finished tied for 21st at 7 over with, among others, Tiger Woods.
The 17-year-old Hossler was the one in contention for the U.S. Open title most of the week, taking the lead for a short time during the third round Saturday. Meanwhile, Spieth made it to the weekend on the cut line of 8-over par after shooting 74 on both Thursday and Friday.
Spieth, who just completed his freshman year at Texas, said his play improved each day as he became more familiar with the intricacies of Olympic.
"I had only played one practice round, so I went into Thursday, I had seen the course, but nothing like after five days of playing it," Spieth said Sunday. "So I think that was a big factor, too, was just knowing which places you can miss and which you just can't."
A Dallas native, Spieth got into the championship when Brandt Snedeker withdrew last Monday, citing a rib injury. Spieth almost had dropped out of his U.S. Open sectional in Houston after arriving there off three hours' sleep following the Longhorns' triumph in the NCAA men's golf championship at Riviera in Los Angeles.
Hossler entered the final round four shots off the lead and told reporters after the third round he "absolutely" had a chance to win the championship.
But he bogeyed three of his first five holes Sunday, then shot a 4-over 40 on the back. His hopes of low amateur honors ended with a double-bogey 6 on No. 18.
"Sure, I was nervous to start the round, no doubt," Hossler said. "Just like every other day I was nervous starting the round, but I felt pretty comfortable coming to the middle and toward the end, but unfortunately made some mistakes coming in that obviously hurt my score."
Still, Hossler said the experience was rewarding.
"There's so much, so many positives for the week," he said. "I played well out of 70 holes, 72 holes I probably played well 60 of them. Made some crucial mistakes, missed some on the wrong side of the holes. But just like from last year, it's only a learning experience, and I still have some time before I come out and start doing this for a living."
Spieth and Hossler have become good friends in the junior golf circuit. Spieth believes he had some influence in Hossler's verbal commitment to play golf at Texas.
"Beau just looks really confident on the course and he's handling himself well off the course too," Spieth said. "So it's just been an all-around great effort by him and cool to see him sporting the Longhorn gear out there."
But on Sunday, Spieth was the top Longhorn.