The 15-year-old Carlin racer claimed his sixth victory of the season to leapfrog Collard to the top of the leaderboard.
Norris then followed it up with a second-place finish in the closest race of the season so far.
It left the ADD Motorsports-supported driver 17 points clear with just six races left and delighted with how the weekend went.
He said: “The first and last race couldn’t have gone much better. We were fast all weekend and the win in the first race was comfortable in the end.
“The second place finish was a really close race and I maybe would have had a chance to win it if I’d had another lap.
“It’s great to be at the top of the Championship again – but there’s a lot of hard work still to come.”
Lando was fastest in both practice sessions and with a good set-up found the same pace in qualifying.
He notched up the fastest lap to get pole in the first race and his second fastest lap was good enough for him to start in second place in the final race.
Full of confidence, he started the first race well and pulled away quickly when he could.
His progression was halted when the safety car was needed on lap two. But he got a good restart and a gap quickly opened up again – and he stayed in the lead to win comfortably.
With the reverse grid on the second race he got off to a decent start, but a knock from behind half way round the first lap let a couple of other drivers past.
He had overtaken one when the safety car was once again needed, but after the restart he overtook another.
However, with the next driver in his sights defending and Lando not wanting to make any rash moves, he could only finish in eighth.
He got off to a good start in the final race of the weekend, but when the leader Herta wheel span he was so close that it slowed him down and allowed his rivals to catch up and one overtake.
Another safety car was needed and after the restart, Lando spent a few laps trying to find a way to overtake second-place Ticktum on the outside.
He finally managed on lap seven, appearing to overtake on the outside, but instead orchestrating a dummy move and taking him on the inside.
Depsite a four second gap to the leader, Lando caught up lap-by-lap, claiming the fastest lap time in the pursuit.
He finished just 0.248s off Herta at the line – for the season’s closest race and a thrilling finale to the weekend.
He commented: “The next race is going to be hard as it’s a close racing track.
“But I’ve got a good chance of winning the Championship, so have to make sure there are no mistakes and keep doing what I’m doing.
“I’m sure it will go down to the last race.”