Mistakes by other drivers, notably Charles Leclerc and Max Verstappen, saw Magnussen surprise fourth after the first round in the final stretch of qualifying.
Leclerc’s crash raised the red flag and ensured that no one could improve their times and relegate Magnussen in their second round.
He survived an obstruction investigation to secure a spot for his American team following an incident with Lewis Hamilton early in the first quarter.
“It feels good,” the Dane said. “It’s a big game for us. The team’s home game, all our big sponsors are here this weekend.
“It’s a game that we want to go through and it’s one of those things. I’m a little bit lucky. But I’m not sad about it.”
Magnussen, who survived a spin and scrape a wall in FP2, said the car – which is undergoing a floor upgrade – was fine from the start of track action.
“I think we’ve been strong this weekend,” he noted. “And not just in terms of lap times, but if you look at the results of each session, it’s been great.
“But it felt that way from the start. We put the car on the track and it worked. We haven’t really touched it yet.
“And I think it’s really good. Then we brought a valid upgrade, so yeah, happy with P4 tomorrow, hopefully we can finish it and get some points.”
On the Hamilton incident, he added: “Me and Lewis were on the slow lap. I was starting another lap. He was pitting. So I don’t quite understand what happened.
“I think he was a little bit under time pressure to start the second round. So he rushed in and I started a new lap.
Magnussen’s teammate Nico Hulkenberg found himself stuck in 12th after hitting traffic on the outer lap of Q2.
“There’s more in the car,” the German said when asked about the Autosport meeting.
“I’m really, really frustrated and frustrated. My time in Q2 was in the new group from the first lap.
“We need to look back at what happened in the outer circle and how we got into a mess with Fernando (Alonso) and Esteban (Ocon). I ended up losing precious time on this and I kind of had to Stopped the car to open the gap with them in the last corner.
“Once you slow down here, when you slow down, there’s something on the tarmac, when you slow down, the tires get a lot of shit and dirt, and then open up a lap and I find myself without the grip I need. fertility.
“I was a second behind in the first quarter and stopped the lap. What’s more, Q3 should be very easy, so it’s very frustrating.”