The reigning British Superbike champion was on top form from the outset at Valencia and started from sixth on the grid for both races.
This was much improved for the Japanese and was the first time he had appeared in the one lap Superpole session that WSBK uses to establish the starting grid for the top 16 riders.
The 25-year-old did not get away very well from the line and had just started to make progress into the top ten when his bike suffered electrical failure in race one.
Again suffering a poor start in race two, the double British champion was soon flying through the field in similar style to team-mate Checa.
He made some forceful moves and in the last two laps moved past Troy Corser into fourth place, his best yet at this level.
"I am really pleased with the result I achieved in the second race after I suffered technical problems in the first race," he said.
"I have not been this close to a podium finish yet and it boosts my confidence that I have been able to increase my speed during the race and overtake riders in front of me."
The third member of the Hannspree Ten Kate team, Kenan Sofuoglu suffered a dismal weekend.
The Turk missed out on Superpole, qualifying 24th out of 30 and in the races was scrapping around in the lower points scoring positions.
He finished 12th in race one, sneaking a point for 15th in the second event.
"Considering all the crashes today I am glad I managed to stay on the bike and finish both races," said the reigning World Supersport champion.
"I cannot be happy with fighting for just one place and taking only a few points home.
"I know the Assen track well for the next round and it's a fast track, which suits my riding style.
Team manager Ronald Ten Kate was upbeat after the showings of Kiyonari.
"Big compliments to Kiyonari, he is showing continuous improvement in race conditions and just gets better and better," said the Dutchman.
"He will need to improve his first laps in the race, as this is where he is still losing his chances of a podium finish.
"Sofuoglu managed to finish both his races and score some points. Hopefully, the next race on our home track in Assen will see a different Sofuoglu.
crash.net
This was much improved for the Japanese and was the first time he had appeared in the one lap Superpole session that WSBK uses to establish the starting grid for the top 16 riders.
The 25-year-old did not get away very well from the line and had just started to make progress into the top ten when his bike suffered electrical failure in race one.
Again suffering a poor start in race two, the double British champion was soon flying through the field in similar style to team-mate Checa.
He made some forceful moves and in the last two laps moved past Troy Corser into fourth place, his best yet at this level.
"I am really pleased with the result I achieved in the second race after I suffered technical problems in the first race," he said.
"I have not been this close to a podium finish yet and it boosts my confidence that I have been able to increase my speed during the race and overtake riders in front of me."
The third member of the Hannspree Ten Kate team, Kenan Sofuoglu suffered a dismal weekend.
The Turk missed out on Superpole, qualifying 24th out of 30 and in the races was scrapping around in the lower points scoring positions.
He finished 12th in race one, sneaking a point for 15th in the second event.
"Considering all the crashes today I am glad I managed to stay on the bike and finish both races," said the reigning World Supersport champion.
"I cannot be happy with fighting for just one place and taking only a few points home.
"I know the Assen track well for the next round and it's a fast track, which suits my riding style.
Team manager Ronald Ten Kate was upbeat after the showings of Kiyonari.
"Big compliments to Kiyonari, he is showing continuous improvement in race conditions and just gets better and better," said the Dutchman.
"He will need to improve his first laps in the race, as this is where he is still losing his chances of a podium finish.
"Sofuoglu managed to finish both his races and score some points. Hopefully, the next race on our home track in Assen will see a different Sofuoglu.
crash.net