Lowes took the race one win after a thrilling final lap and Byrne edged a photo finish in race two as the pair set up a thrilling finale at Brands Hatch in Kent in two weeks' time.
Despite a big crash on Saturday Byrne took the lead on the opening lap of Sunday's first race on his Rapid Solicitors Kawasaki.
Lowes claimed the lead on the Samsung Honda and the retirement of Josh Brookes from third saw that place taken by his Tyco Suzuki team-mate PJ
Jacobsen only for Tommy Biridewell to snatch the final podium place late in the race for Milwaukee Yamaha.
Lowes and Byrne swapped the lead on a thrilling final lap only for Lowes to win the race to the finish line and move four points ahead of Byrne in the title race.
Race two saw Lowes and Byrne again battling for the race victory and this time there was even less between the two title rivals by the time they crossed the finish line.
Byrne edged the victory after a photo finish to move back into the points lead, albeit by the narrowest of margins going into the final two races of the season at Brands Hatch.
Bridewell again filled the final step of the podium in race two at Silverstone.