Starting from a 2013 best of fifth on the grid, Nicky Hayden couldn't hide his disappointment at crashing out early in Sunday's race.
Hayden lost the front of his Ducati, like many others, as he turned into the left hander at the end of the back straight, on lap 6 of 25.
The 2006 world champion had just retaken fifth from Stefan Bradl, after dropping back to eighth on lap one.
“I got a pretty good jump on the start, but some guys overtook me going to turn one,” said Hayden. “I had to make a few passes and once I got into fifth I wanted to do a couple of clean laps and see what kind of pace I had.
“But as soon as I got off the brakes at the end of the back straight the front folded before I could do anything.
“It's really frustrating because it was the best weekend of the year as far as pace goes and to end up in the gravel trap hurts. I don't see why we couldn't have got our best dry result of the year.
“There's nothing we can do now but take it on the chin.”
Asked to compare how his Desmosedici was working relative to Bradl's factory-spec Honda, Hayden replied.
“In a couple of places I had more grip than him. There were some places where he had a little better acceleration with the bike picked up, but I'd managed to get a run on him and pass him into turn one. Then the next two splits were my best of the race...”
Like most of his rivals, Hayden will be back on track at Catalunya for Monday's post-race test, where he and team-mate Andrea Dovizioso will again ride the development 'lab' bike.
“We'll test the ['lab'] bike tomorrow and see how that goes. See if we can find some potential with it and make it as good as our standard bike, then decide what we do for Assen.”
Dovizioso finished seventh in Sunday's grand prix, over 30-seconds from race winner Jorge Lorenzo (Yamaha) at one of the toughest tracks for the GP13.
The Italian liked the 'lab bike at the previous Mugello test - although it didn't produce much of a difference in lap time - and confirmed that Monday's track time is likely to decide if it will be raced by the factory team at Assen.