Playing in a group with three Indians, perhaps the only time this has happened outside India in an international golfing event, Thomas outscored even Anirban Lahiri (69) and SSP Chawrasia (77) and showed his immense potential, which earned him praise from Lahiri.
Lahiri carded 69, but that may well have been a five-under or even better as he missed two short par putts on his 16th and 17th holes, which were eighth and ninth holes of the Majlis Golf Course at the Emirates Golf Club.
The lead was in the hands of the mercurial Sergio Garcia, whose seven-under 65 was one better than Felipe Aguilar of Chile and South Africa's George Coetzee. Four others including Ian Poulter and David Lipsky were tied-fourth at 67.
Tiger Woods, whose appearance had raised a lot of interest the world over, had a forgettable day that had five bogeys and no birdies. It was the first time he had not birdies in a round at Dubai, where he has won twice.
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Despite being praised all around, Thomas, who has even won a pro event at 16 on the MENA Tour in the Middle East, refused to get ahead of himself.
"I am not really thinking about making the cut, but it would be awesome to make the cut in I guess my 'home' open, as I am based in Dubai," he said.
"When you play well it's easy, when you play bad it's difficult. The wind picked up on our back nine, which was our front. It got a bit tricky on the front but I just kept my head and it was a good day. I can't complain; holed a few putts; hit some really good iron shots and had a chip in on five."
Thomas, who was five-under before dropping a late bogey, added, "For my first round at the Dubai Desert Classic that group was perfect. Two (Lahiri and Chawrasia) really great guys and I'm glad I played with them this week."
Lahiri, whose own 69 included two misses on makeable par putts, misses towards the end, was all praise for Thomas, saying: "He had a great day and shows immense potential.
In his own round, Lahiri was five-under through 15 holes, which included a great 50-footer for eagle from edge of the green on 18th, his ninth hole.
Lahiri has played at the Dubai Classic only once before in 2010, when he got an invitation but missed the cut.
Meanwhile, Woods said, "Hopefully this wind blows tomorrow and I shoot a good round and get back to even par now. That's certainly not out of the realm of winning the golf tournament. The last two drives I hit off of eight and nine today, there's something different. I need to figure out what the hell I did that was different and then replicate it for hopefully another 54 more holes.