Little over a month ago, the 21-year-old was laid low with glandular fever and able to do nothing more than sleep and watch TV with her father Ian at home in Guernsey.
Watson began practising again only three weeks ago so it was a considerable achievement that she was on the court at all at Roland Garros on Wednesday for the match against Stefanie Voegele of Switzerland.
There is clearly work to do for Watson on fitness and match sharpness but the British number two, who rated herself at 90-95 per cent prior to the tournament, is not too far away.
In the second set she played well, winning four straight games to take it with some crisp forehand winners, but Voegele responded in the decider to win 6-4 2-6 6-4.
Watson still has women's doubles and mixed doubles in Paris before heading back to London to begin work on the grass.
She said: "I think being in a match situation and playing matches definitely helps, because naturally you want it, so you're trying a lot harder, using your muscles a lot more, whereas in practice you're more relaxed and playing freely.
"So I think this has helped me. It's a shame. I wanted more matches under my belt. But I'll just work from here, get in the gym, do stuff to get fit for the grass.
"I'm pleased with how I played in the second and third. I was aggressive. I was hitting it. I've just got to get better from there."
The key moment of the match came when Watson was broken at the start of the third set after Voegele had taken a toilet break.
It is an open secret that many such breaks are often primarily tactical, but Watson felt she should have kept her concentration better.
It is on the mental side where Watson feels the missing weeks really showed, saying: "I think there's two main things for me.
"It's being ready for the next shot and getting ready. I'll just hit a serve and kind of stand there and expect it to come back to me. So that's one thing.
"And also just focus, point in, point out, the whole way through a match. I lost that a bit."