Northern Ireland's Glenn Irwin took two wins at the British Superbike round at Cadwell Park, with his Ducati team-mate Tommy Bridewell winning the third race.
Irwin's double, plus a runner-up spot in race three, reduced his deficit to series leader Bridewell to 14.5 points with three race meetings remaining.
Having taken victory on Sunday, Irwin worked his way through the field to win Monday's opener from Kyle Ryde.
Irwin was edged out by Bridewell in a thrilling second race of the day.
The Carrickfergus rider started from the third row of the grid for Monday's race but a series of superb passes saw him challenge at the front after early leader Ryan Vickers crashed out.
The 33-year-old overtook OMG Yamaha rider Ryde on the straight going onto the final lap and maintained his advantage to take victory by 0.46 seconds, with Jason O'Halloran, Leon Haslam and Bridewell rounding out the top five.
In Monday's second event, Haslam and Ryde enjoyed spells at the front, but Irwin stormed through from eighth spot on the grid to assume the lead on lap eight.
Bridewell chased down his title rival however, hit the front on the 16th lap of 18 and won the race to the chequered flag by 0.057 seconds.
The Cadwell round completes the regular race season, with the three 'Showdown' rounds beginning with three races at Oulton Park in mid-September.
Alastair Seeley was third in the National Superstock event, behind race winner Tim Neave and championship leader Dan Linfoot.
Synetiq BMW by TAS Racing pilot Seeley sits third in the overall standings on 181 points, with Linfoot (254)enjoying a 27-point lead over Donegal's Richard Kerr (227).
Kerr was forced to take to the gravel on the opening lap of the race at Cadwell, but recovered to finish in 10th position and salvage some potentially crucial points.
Eglinton's David Allingham was seventh in the Superstock outing.
In the Supersport class, another Donegal rider Rhys Irwin, came home third, with Ben Currie securing a fourth consecutive win and Richard Cooper second.
Irwin lies second in the series, 44 points adrift of pacesetter Currie.
British Superbike Championship standings
1. Tommy Bridewell (Ducati) 303 points
2. Glenn Irwin (Ducati) 288.5
3. Kyle Ryde (Yamaha) 252
4. Jason O'Halloran (Yamaha) 248.5
5. Leon Haslam (BMW) 227