Slovakia's Matej Toth denied Jared Tallent an outright Olympic gold when he came from behind to beat the Australian for first place in the 50-kilometre walk at the Rio Games Friday.
The reigning world champion Toth took the lead with 2km left in sweltering conditions to claim his nation's first ever Olympic athletics medal.
The women's 20km race later also saw the world champion prevail, with China's Liu Hong edging ahead of Mexican contender Maria Gonzalez on the final metres.
Toth crossed the line draped in a Slovakian flag and after high-fiving a few supporters, clocking 3 hours 40 minutes 58 seconds.
"It's everything. In sport it's something unbelievable for me. Something like immortality in sport. I'm so proud. So happy," the delighted Toth said.
Tallent trailed by 18 seconds for silver. Hirooki Arai of Japan finished got bronze with a 26-second deficit but his medal was not decided until several hours later.
The jury first disqualified him via a Canadian appeal for obstructing Evan Dunfee who moved up to third. But Arai was reinstated as bronze medallist via another protest from Japan some six hours after the race.
Tallent was promoted to gold from London 2012 after the initial Russian winner Sergey Kirdyapkin was disqualified. He received the medal at a special ceremony two months ago in Melbourne and had hoped to climb the top of the podium outright in Rio.
But his lead of 22 seconds over Toth at 45km did not last as he had to settle for his sixth minor medal overall from world championships and Olympics.
"I wanted to win. That was the main aim after what happened in London. Getting the gold medal so late, and to be an Olympic champion for more than a few months," Tallent said.
"I gave it everything, but probably went a little bit too early. At the 40km mark I was feeling really good, so I thought I'd put in a big lap and try to make the break then. But I really paid for it with about 4km to go. Then Matej caught me with about a lap to go and I just had nothing in the legs. Just couldn't hold on."
Yohann Diniz of France, the fastest walker of the year and early race leader, collapsed several times but did grind it out to finish eighth, almost six minutes off the pace.
Liu meanwhile returned from a recent month-long suspension after being caught using a forbidden fat burner, topping the women's race in 1:28:35 minutes.
Gonzalez trailed by two seconds for Mexico's first ever medal in the event while bronze went to China again in the form of Lu Xiuzhi, another five seconds behind.
The evening session in the stadium was to see five further finals highlighted by the men's 4x100m relay where Jamaican superstar Usain Bolt aims to complete a unique third sprint treble.