Kathmandu (CNN) -- A fight for supremacy between two octogenarian climbers is heating up on the slopes of the world's highest mountain. Eighty-year-old Japanese national Yuichiro Miura is on his way home after becoming the oldest climber to reach the summit of Everest on Thursday. But his achievement may soon be overshadowed as his old rival, veteran Nepali climber Min Bahadur Sherchan, 81, acclimatizes at base camp, ready to reclaim his title. The two mountaineers first clashed in 2008, when Sherchan, then 76, reached the 29,028-foot (8,848-meter) peak a day before Miura, then 75. However, it was Miura's ascent that made it into Guinness World Records, forcing Sherchan to travel to London to set the record straight.
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Japan's Yuichiro Miura, 80, is on way home after becoming the oldest climber to scale Everest
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Record may already be at risk as 81-year-old rival acclimatizes at base camp
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The pair have a longstanding rivalry since Sherchan claimed the title in 2008
"I think three times is enough," said @placeholder, who made his first ascent at the age of 70.