Jamie's first run in the women's slopestyle was enough to put her in the top 6 and earn a qualifying spot. But it was her second where she really stepped it up, answering the challenge thrown down by Canadian Spencer O'Brien and Switzerland's Isabel Derungs, the owner of probably the best backside rodeo in women's snowboarding.
Jamie's corked cab 5, front 7 and backside 5 over the kickers, combined with a clean rail section, took her straight to the top of the leaderboard. Commentator Jack Mitrani was so confident of her first place he called it before the judges had.
Whitelines had been hoping to see the UK's Aimee Fuller competing alongside the other ladies in the field, but unfortunately a stomach bug meant she didn't start.
In the men's event two Brits did drop in. And although Billy Morgan and Jamie Nicholls were both carrying ankle injuries both rode well. Jamie landed two clean runs, showing probably the best rail skills of anyone in the field - cab 450 hardway on and 50-50 to backside 540 Unfortunately his kicker combo of cab 10, switch back 9, frontside 10 didn't score so highly.
Billy was more unlucky. According to Mitrani's co-commentator (and fellow Brit) Henry Jackson, he'd nailed himself quite badly on a frontside double cork 10 in practise and while the rest of his run looked pretty good, that trick was clearly giving him nerves. First time around he over-cooked it and but-checked, while the second time he took off too much speed bouncing off the knuckle.
Neither Brit's best score was ever going to trouble the leaderboard in the talent-packed field - with a few noticeable exceptions (Chas Guldemond and Torstein Horgmo were out injured, Olympic gold medallist Sage Kotsenburg was riding powder with Halldor in Austria) the start list read like a who's who of slopestyle snowboarding. McMorris, Toutant, Smits, Parrot, Piiroinen, Kadono, Braaten, Tonteri... they were all there.
Alongside these super-stars it was nice to see a few unknowns - five to be precise - who'd qualified through from the "open" stage of the competition, which these days is held as a separate contest in Pennsylvania. And although a lot of the big guns qualified through (Roope Tonteri's run in particular was worthy of a mention) it was also refreshing to see a few (relatively) new faces near the top of the leaderboard - Brandon Davis, Tyler Nicholson and Darcy Sharpe all qualified in style, as did former Burton super-grom Kyle Mack.
None of these could quite touch Stale though. His frontside to backside lipslide switch-up on the first rail combined with a cab 12, front 10, backside triple 14 combo on the kickers just blew everyone out of the water. Bearing in mind this is only the semi-finals, the bar has been set - and set high. We can't wait to watch the livecasts of the finals starting with the women at 5pm GMT on Friday and the men at 7pm.
Meanwhile keep your eyes on the livestream for the men's and women's halfpipe semi-finals this afternoon.
Burton US Open Women's Slopestyle Semi-Final Results.
1. Jamie Anderson (USA) 86.80
2. Isabel Derungs (SUI) 78.45
3. Spencer O'Brien (CAN) 78.25
4. Miyabi Onitsuka (JPN) 77.25
5. Ty Walker (USA) 74.15
6. Cheryl Maas (NED) 70.80
Men's Slopesyle Semi-Final Results.
1. Stale Sandbech (NOR) 87.05
2. Brandon Davis (USA) 81.30
3. Roope Tonteri (FIN) 80.85
4. Kyle Mack (USA) 77.05
5. Tyler Nicholson (CAN) 76.25
6. Sebastien Toutant (CAN) 75.70
7. Darcy Sharpe (CAN) 74.85
8. Maxence Parrot (CAN) 74.30
9. Mark McMorris (CAN) 73.85
10. Emil Ulsletten (NOR) 72.05