My Britgo summary tells the story: I won against Jonas Welticke 6d by resignation, bring me to an unbelievable 10/10 on pandanet! This was supposed to be my toughest test so far, so while maths has been prioritised this term, I tried to study go for the last 2 weeks, particularly define 3.0 on the computer Go server.
He opened adventurously with four 11-3s. Especially as I wanted to play territorially anyway, this set bells ringing in my head that this should be a territorial game (hard to make frameworks, so I focused on the corners). He invaded 3-3 into my star point and his result was poor when I took the corner (the 10-3 was an inefficient one space extension from a ponnuki). He attached star point on my komoku, I took the corner and I was happy. He attached 3-3 on my other komoku, and I was very happy to take a very large corner.
He finally invaded 3-3 into my other star point, I played good direction, but overlooked a severe cut, when he blatantly had more ko threats. However, instead of ending the ko to get a good result, he made the ko even bigger. He played a poor ko threat worth around 25 points. Ending the ko, I got a massive corner territory plus thick influence, and he had a wasted stone on the outside.
Furthermore, he overlooked a lovely tesuji I had for liberties in the semeai, and a horrific bulky 6 tesuji, so even his follow up to his ko threat died on a large scale. So by move 90, I already had 80 solid territory points compared to his 20 or so. He had to place his hopes on the centre.
I decided I still wanted an interesting game, and played daringly into the centre, but a peep overplay and a big blunder on the upper left, meant my group in the centre wasn’t clearly alive. However, his position was just too thin and eventually I captured another 50 point group with my centre group.
Unfortunately I then realised I had 2 seconds to play 2 moves. So I was frantically power-clicking S19, a move worth around 200 points just in case he ataried it. I wouldn’t mind if he got three moves elsewhere, as long I could play S19 (and maybe S18 to fill my own territory) and get into the next time period. He tortured me for 7 minutes like this! But he honourably resigned. I could have cried in relief.
https://www.lifein19x19.com/download/file.php?id=9087
I was almost as nervous as my first few league games, against a 2592 player, when the UK were fighting for top spot in the league. I don't think it was that I played well, just he made it very easy for me with his weird opening and direct 3-3s/3-4s as I didn't have many options and needed little thought to find a good move.

I'd consider 3-3 next time, but I'm happy with my choice too

In hindsight, extending the other direction should be better as in the game my 4-4 got hurt. I was concerned about him living in the corner, but that is a minimal concern

fighting spirit, and it makes his efficiency look bad locally, but perhaps a solid defense in the corner was proper. hmm, hard to find a good move though. I definitely had to add a move, but it was hard to choose where, or if I should have quit extending at some point earlier and fixed. My personal judgement was 70% in my favour.

seems approach C14 is obvious, if I retreat knight's move, he can still play 3-3, and it may be more severe.

yes, should just extend. Was planning too, and then wanted to ask for more. Actually, I just didn't consider him cutting.

clearly he didn't want to play P19 so as not to let me live, but this way around he wasn't alive.

nice to see my tesuji took 1s

my bulky 6 took 2:30 to verify! If this wasn't necessary or didn't work, this move would be too embarrassing, because the simple S13 would lead to a very good result for me anyway. I did read the game variation but thought he could have done better with R13 or S13 instead of T16. My personal win expectation was well over 90% by this stage.

a mistake in hindsight, just fill liberties. edit: the comments are correct, the poke works if I continue at P12, but I misjudged some variations and thought there was some messy ko, when P12 is clearly far better than the game.
w132 just play a little more solid should be a lot better
w150 should be D18
I wouldn't be too surprised if my centre group was killable at some point. I don't think Jonas played the best moves.