The first Grand National Twins event of the season was won by South East Harley rider Sammy Halbert on a Harley-Davidson XR750 motorcycle.Racing for the first time on the Stockton half-mile, Coolbeth finished sixth in his heat race and then earned the last starting slot for the main with a third-place finish in a semi-final heat. Coolbeth’s pace improved in the main, and he quickly moved up to 11th place in the early laps, and then worked into the top-ten and passed R&J Racing rider Doug Lawrence on the last lap to secure seventh position.Kenny Coolbeth says: “Most of the Grand National teams have never seen this track before, and it kind of came down to who would figure out the set-up first. The track surface was great but the corners are tight and it felt small, like a short track. We got it figured out by the main and ran pretty well, but the starting spot ruined our chances to race up front.”Halbert and Dodge Brothers Racing rider Brad Baker raced together at the front of the field for the entire 25-lap main, officially swapping the lead seven times and never separated by more than fractions of a second. The 20-year-old Baker was vying for his first career Pro main victory, and Halbert was racing for the first time this season after recovering from knee surgery.Halbert made his final pass for the lead on lap 20 and then held off the charging Baker in the closing rounds to win by 0.961 seconds. Lloyd Brothers Motorsports rider Henry Wiles was third, 4.710 seconds behind the winner, as Harley-Davidson XR750 riders filled the podium. Zanotti Racing/Schaeffer’s Harley-Davidson rider Jake Johnson was fourth, followed by Weirbach Racing rider Robert Pearson and Kawasaki rider Brandon Robinson.The defending series champion, Rogers Racing/Blue Springs Harley-Davidson rider Jared Mees, won a heat and the four-lap Dash for Cash bonus sprint, but nearly crashed early in the race after contact with Wiles. He recovered but dropped to last place and finished 16th.Robinson now leads the AMA Pro Grand National Championship series with 55 points. Baker is second with 48 points, followed by Wiles with 47 and Johnson with 45 points. Coolbeth is in sixth place with 35 points.The next race on the AMA Grand National Twins schedule is May 26 on the Springfield Mile at the Illinois State Fair Grounds in Springfield, Ill.