He needed to finish in the top five to clinch it and pulled off a third place to secure his number one in the Championship.
The race win actually went to Gregorio Lavilla on the Airwaves Ducati with Kiyo's team-mate Jonathan Rea coming home in second.
Off the line it was the two black HM Plant Hondas who got away first. Kiyo got a blinder of a start from the second row to slot into second place behind Rea. They were being hounded by Tom Sykes on the Stobart Honda, with Lavilla and his team-mate Leon Haslam following.
Rea got his head down and started to pull a gap over Kiyo. On lap eight Lavilla started to move forward taking Sykes for third place. He also picked up the lap record with a time of 45.708secs.
Sykes who was pushing hard lost the rear on the run onto the Cooper Straight. He was ok but as his bike slid along it caught fire in spectacular fashion. This incident brought out the Safety Car for three laps allowing the riders to bunch up.
While the Safety Car was still on track Martin Jessop managed to crash out unhurt. Lap fifteen saw Lavilla make his move on Kiyo at Paddock Hill bend as he had been stalking him for a number of laps. He now had to reel in Rea who had a lead of 0.405secs at this point of the race.
Both the Hydrex Hondas disappeared mid race with both Karl Harris and Aaron Zanotti crashing out in separate incidents. On lap nineteen, Lavilla made his decisive move on Rea as he was all over the back of him by now. He nabbed the lead at Clearways and pulled away gapping Rea by 2.317secs at the end of the race.
Haslam who had been hoping to pick up the title finished in fourth place ahead of Cal Crutchlow on the Rizla Suzuki. Shane Byrne on the second Stobart bike got a woeful start and finished the race in sixth.
Chris Walker put in a sterling performance to finish seventh following his big crash during Saturday's free practice. He didn't suffer any broken bones but he was feeling very battered and bruised.
Isilon MSS Discovery Kawasaki's Michael Rutter also bounced back from his crash earlier in the weekend to take eighth. While Simon Andrews and Steve Plater completed the top ten.
BSB race results (1) – Brands Hatch:
1. Gregorio Lavilla
2. Jonathan Rea
3. Ryuichi Kiyonari
4. Leon Haslam
5. Cal Crutchlow
6. Shane Byrne
7. Chris Walker
8. Michael Rutter
9. Simon Andrews
10. Steve Plater