The Honda rider pushed hard from the off in Thailand as he came to Buriram feeling like his recovering right shoulder could stand up to the strain.
Fastest in FP1 and qualifying eighth, Marquez went on to finish the rain-lashed Thailand race fifth and only missing out on victory by 2.9 seconds.
But he admitted afterwards that he was glad of the wet conditions, as his arm felt "horrible" in the dry warm-up session on Sunday morning.
"I mean, of course I'm very happy," Marquez said when asked to assess his first three races of his MotoGP comeback from a fourth major right arm operation.
"Honestly speaking, the rain conditions saved my life. It was the first weekend where I approached the weekend full attack from FP1, and I was riding as you saw on TV; aggressive, moving the bike, [managing] some shaking, saving the crashes.
"But [on Sunday] I got up and the arm was very stiff. In the warm-up the feeling was horrible, but then I worked in the Clinica and in the race I was able to race in a good way.
"There was not any limitations on the physical condition.
"But we cannot forget that it's working well, it's inside the normal steps in rehabilitation, especially when you do three races in a row in your comeback."
Marquez fought with Ducati's Francesco Bagnaia late in the race for the final spot on the podium, but would eventually find himself behind Pramac's Johann Zarco.
The Honda rider says he was unable to find a place to force an overtake on Bagnaia because of the usual "problem when you are behind Ducatis".
"I did a solid race a bit like in Motegi. I started calm, step by step I found my rhythm and I warmed the tyres in a good way," he added.
"Maybe in the first five laps I could have taken more risk, but I just said 'OK, it's time to do this kind of race now I believe'.
"I was coming faster and faster, but it's the problem when you are behind some Ducatis. To overtake, you need to be much, much faster because they are braking so late, stopping the bike and especially [they have] amazing acceleration.
"It's there where I catch Pecco, I didn't find a place to pass him because I was just a bit faster than him but not enough.
"And then when Zarco overtook us, just from one corner to the next he was parallel. So when you have a good speed in this situation it's easier. Apart from that, I'm very happy about my weekend."
