Mercedes driver Lewis Hamilton says he "can't believe" he managed to come from the back to finish third in Sunday's Belgian Grand Prix.

Hamilton lined-up 21st on the grid having picked up a raft of penalties for three pre-planned engine changes.

However, thanks to an incident-packed start, with Max Verstappen and the Ferraris colliding into Turn 1, before Kevin Magnussen crashed heavily at Eau Rouge on lap 6, he found himself up to fifth when the race was red flagged.

Verstappen will cause a massive accident, warns Raikkonen

At the re-start he then made further progress, passing McLaren's Fernando Alonso and Force India's Nico Hulkenberg, before eventually bring his car home third, a result that sees him retain his Championship lead, 9 points up on team-mate, Nico Rosberg, who took the victory.

"I really can't believe we came up so far, to be honest," Hamilton confirmed. "I woke up this morning knowing how difficult it would be on these tyres, lots of blistering, but you can never predict what is going to happen in a race.

"That is the great thing about motor racing. Since I was 8 years old, every race, every Sunday, has been different. The car is positioned a different way, the start is a bit different, something happens up front, previous races there was no incidents and today there was. Today was really about trying to approach it with the right approach and not be too aggressive, not too easy.

Verstappen defends himself - 'It's good TV if somebody is moaning...'

"I think today collectively as a team we had just the right balance and this is the best result I could have hoped for."

Asked how much the safety car period and red flag had helped him to recover to third, Hamilton replied: "That was obviously a part of it. I think I was already up to fifth or sixth though before the red flag. But of course there was things I needed in the race to help progress through. As I said, I didn't know how long these tyres would last. I think our performance today was stronger than I expected and so I think still at the pace we were going, I think a top-ten finish was still possible. But third was definitely helped by the safety car and the VSC."

RESULTS: Belgian Grand Prix - Race results

Meanwhile, Hamilton said he was 'proud' of the way the team manage his three pre-planned engine changes this weekend.

"It has obviously been a much different weekend to anything I have ever experienced," he continued. "I am incredibly proud of all my guys in the garage and all those at the factory for building these engines and changing these engines this week. We had three new engines this weekend and so, to come away with the points we have today, I am extremely proud of everyone. I honestly didn't know what was going to happen in the race and I was just trying to keep my head down all the time and focus on the long run pace.

"It seemed to work and congratulations to the lads. It is great for Mercedes and still great for the championship [too]. If I had known this, I would have had an even better summer, if I had went into it knowing I would still be nine points ahead after three new engines. I am very grateful."

Latest Tweets from & GPF1rst