"I was stuck behind Kamui but we were nowhere on the straights," he continued. "Also our tyres were suffering and we were not quick enough to fight, to go through the field because the car was damaged. I looked at the floor [after the finish] and it didn't look nice."
And that wasn't the end of it: along with the worsening conditions, Vettel also lost the ability to speak to his pit wall over the team radio, although he could still hear them. That led to confusion and miscommunication when it came to a crucial mid-race pit-stop.
"With the damage on the car, losing radio, in these conditions, when communication is so crucial," he agreed. "Stopping just a lap too early, not having the tyres ready because communication wasn't there.
"We probably did the pit stop at the wrong time," he continued. "I went on another set of dries; a lap later it started to rain. Came in for inters, the inters weren't ready because we had no radio communication, they couldn't hear me."
That cost him a lot of time, but was nonetheless the right call as the conditions deteriorated with the rain picking up in the latter stages of the race. The inclement weather also helped level the playing field and reduced the performance deficit of the damaged Red Bull.
"We obviously caught back up in the wet in intermediate conditions," agreed Vettel. "In wet conditions I think you can make up a little bit of time here and there ... You can make up for the loss of car pace that you have by probably driving a different line and trying to do something different to others.
"We had our hands full to keep the car on the track," he added. "It was very very difficult to drive the car. I was very aggressive and snapping quite a lot, so I lost the rears many times. Fortunately stayed on track most of the time!"
The race came to a premature end when Paul di Resta had a big crash two laps from the finish, which put the safety car out - but Vettel still hadn't been sure at that point where he was or where Alonso was positioned.
"I didn't know where I was for most of the time," he admitted. "Obviously I saw which position I was in on the pit board but I didn't know where Fernando was. To make out whether it was enough or not, I needed to where he was but that was not the main focus for the whole race.
"I saw the crash between Nico and Hamilton, obviously retiring, so Hulkenberg and Hamilton out of the race," Vettel explained. "I knew that Fernando was ahead, and they were ahead of him at the time that I could see during the first safety car, so I didn't know.