Barr battled through the pain barrier to take two top ten finishes after qualifying fifth fastest.
He finished ninth in race one and improved to take seventh in the second race after the REVO Husqvarna recovered from an early crash.
Barr now lies fourth in the European Championship as he heads to Canada Heights for round three of the Maxxis British Championship this weekend.
“I didn’t do too many laps in qualifying on Saturday to protect my injuries from Culham a couple of weeks ago, so I was happy with fifth fastest,” he said.
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“In my opening moto I was up to sixth but I was really struggling with my thumb and dropped to ninth.
“The overnight rain made the track deep and heavy on Sunday.
“I was fourth away from the gate but crashed on the opening lap and had to fight back from 20th to finish seventh at the flag and sixth overall.
“I’m now fourth in the championship, 11 points behind the leader, so if that’s my bad weekend I’ll take it. Championships are won on bad weekends.”
Meanwhile, in the MXGP Carrick’s Graeme Irwin had a weekend to forget as he failed to score any points at round five in Portugal.
The ASA Hitachi KTM rider explained: “I was feeling ill on Friday and just got worse as the weekend progressed. I was in the points in race one then had a small crash and decided to pull in and save myself for race two.
“Again I was in the points running in 19th place but was feeling so bad couldn’t hold on and dropped to 21st.
“I will be glad to get home a take a couple of days in bed and get well for this weekend’s Canada Heights British Championship round.”
The next round of the world championship is in Russia on May 1.