The skipper of Abu Dhabi Ocean Racing was forced to quit racing on the very first night of the previous edition in 2011-12 when the mast of his boat was snapped in two by a Mediterranean storm.
In complete contrast, the team sailed the perfect race in the 6,487 nautical mile (nm) opening leg from Alicante to Cape Town that took 25 days, three hours and 10 minutes to complete.
But they were chased all the way by Chinese outsiders, Dongfeng Race Team, who finished a mere 12 minutes behind after the marathon voyage through the Mediterranean and Atlantic.
Walker refused to sleep for two days to ensure his boat finished first into the South African city. Instead he alternated with stints at the helm and down in the cabin, poring over the satellite tracker system.
The boat's onboard reporter, Matt Knighton, painted a vivid picture of Walker and his anxieties.
"Wearing his stress and nervousness onboard, Ian hasn't been able to sleep. His eyes are bloodshot, he's jumped for each perceived decrease in boat speed and his familiar humour is subdued under a quieter exterior," he told Race HQ.
After crossing the finishing line under Cape Town's famous Table Mountain under bright blue skies, 44-year-old Walker's relief was obvious.
"It's quite emotional actually, Walker told Race HQ, minutes after crossing the line.
"I didn't think I would be - but that last couple of hours, they threw everything at us," he smiled,
"We've had people ride on our heels for the last 10 days or so. I must congratulate Dongfeng, an absolutely fantastic performance."
Dongfeng were big outsiders to excel in the opening stage of the 38,739nm, nine-month race that will conclude in Gothenburg, Sweden on June 27 next year.
They included two rookie Chinese sailors in their eight-man crew , Jin Hao Chen and Jiru Yang, who have never sailed around the world before.
But their French skipper Charles Caudrelier sailed a brilliantly judged race and several times came close to overtaking Abu Dhabi in the final miles.
The rest of the seven-strong fleet, which includes teams from Netherlands, Denmark, Turkey/United States, Spain and Sweden, are expected to finish over the next three days.
After a maintenance period, the boats will set sail again on November 19 for the second stage to Abu Dhabi.