Kiyonari had been struggling this season up until this weekend
Japanese rider Ryuichi Kiyonari was the surprise double winner in the British leg of the World Superbikes championship at Brands Hatch.
The reigning British Superbikes champion, who had not won in World Superbikes before, beat Troy Bayliss in race one and Noriyuki Haga in race two.
Championship leader Bayliss started well in race two but finished 11th.
But with four championship rounds left, the Australian is still 82 points ahead of nearest rival Max Neukirchner.
Honda rider Kiyonari did not have the best start to the first race but patiently worked his way up through the field before getting Bayliss in his sights, and finally gaining the inside line on lap 21.
The second race was less of a struggle for Kiyonari, who took the lead on lap 10 and held off the challenge of his compatriot Haga to win by 1.8 seconds.
"I had a lot of pressure from Haga in race two and on many corners it made me
make mistakes," he admitted afterwards.
"I am very happy for the wins."
The next round of the championship takes place in four weeks' time at Donington Park.
But events at Brands Hatch were overshadowed by a serious crash in the Supersport race.
Honda rider Craig Jones had to be transferred to hospial by air ambulance after suffering serious head injuries in a crash at Clark Curve and has been placed in a coma to stabilise his condition.
Jonathan Rea was awarded the race win, with championship leader Andrew Pitt in third.
Race one result:
1 R Kiyonari (Jpn) Honda 36:18.607
2 T Bayliss (Aus) Ducati @ 0.137
3 M Biaggi (Ita) Ducati @ 0.180
4 Y Kagayama (Jpn) Suzuki @ 5.733
5 F Nieto (Spn) Suzuki @ 6.499
6 C Checa (Spn) Honda @ 6.984
7 M Neukirchner (Ger) Suzuki @ 8.300
8 T Corser (Aus) Yamaha @ 10.732
9 J Smrz (Cze) Ducati @ 16.547
10 R Rolfo (Ita) Honda @ 16.569
Race two result:
1 R Kiyonari (Jpn) Honda 36'14.904
2 N Haga (Jpn) Yamaha @ 1.848
3 T Corser (Aus) Yamaha @ 8.883
4 M Neukirchner (Ger) Suzuki @ 11.180
5 F Nieto (Spn) Suzuki @ 12.928
6 M Fabrizio (Ita) Ducati @ 13.696
7 T Sykes (GB) Suzuki @ 13.872
8 C Checa (Spn) Honda @ 14.009
9 J Smrz (Cze) Ducati @ 19.065
10 L Lanzi (Ita) Ducati @ 19.864
11 T Bayliss (Aus) Ducati @ 20.479
World championship standings (after 10 rounds):
1 T Bayliss 334 pts
2 M Neukirchner 252
3 T Corser 252
4 C Checa 233
5 N Haga 230