Suntory Sungoliath showed no seasonal goodwill to local rivals Toshiba Brave Lupus on Sunday as they won the Fuchu derby 28-24 at Ajinomoto Stadium.

The result ensured Toshiba could not finish in the top two of the Red Conference in the Japan Rugby Top League, and they will now play off for fifth to eighth spot in the league.

"It's really disappointing not just to lose but for our season to be over," said Toshiba captain Richard Kahui. "We have been growing as a team and not to get the win and the five points we needed is bitterly disappointing."

Suntory, who finished the regular season top of the red group, will play Yamaha Jubilo in the first round of the playoffs to determine the league champions -- which doubles this year as the All-Japan Championship -- while Panasonic Wild Knights will take on Toyota Verblitz.

Panasonic finished the regular season top of the White Conference and unbeaten thanks to a 44-19 victory over Yamaha, while Toyota finished runners-up to Suntory following a 39-33 win over Kobe Kobelco Steelers.

In the day's other games, NTT Docomo Red Hurricanes beat NEC Green Rockets 16-13, Ricoh Black Rams topped Canon Eagles 40-24, Kubota Spears defeated NTT Communications Shining Arcs 23-17, Kintetsu Liners downed Coca-Cola Red Sparks 36-20 and Toyota Industries Shuttles edged Munakata Sanix Blues 17-15.

Toshiba, Kobe, Ricoh and NEC will battle it out for fifth to eighth spot when the playoffs start on Jan. 6, while NTT Comms, Kubota, Canon and Toyota Industries will contest ninth to 12th.

NTT Docomo, Kintetsu, Sanix and Coca-Cola make up the bottom bracket of the playoffs and will play for 13th to 16th place.

The bottom side is automatically relegated while the other three play one-off promotion/relegation games against the teams finishing second to fourth in the Top Challenge League -- Hino Red Dolphins, Mitsubishi Sagamihara Dynaboars and Kyuden Voltex.

Honda Heat ensured they would be automatically promoted to the top flight by winning the national second division with a 55-10 victory over Hino.

At the stadium that will host the opening game of Rugby World Cup 2019, Toshiba dominated the first 40 minutes but only turned around 12-10 up.

Coenraad van Wyk scored a try and conversion and Hiroki Yuhara also touched down as the Brave Lupus spent most of the half in the Suntory 22.

That there was just two points between the sides at halftime was the result of some resolute defense from the defending champions, who also came away with points on the two occasions they ventured deep into Toshiba territory.

Takaaki Nakazuru finished off a passage of play that started with a 60-meter break from his own line by Campbell Magnay, Matt Giteau added the extras and Ryoto Nakamura kicked a penalty.

Two penalties from Nakamura in the opening 13 minutes of the second half saw Suntory retake and then stretch the lead, before Toshiba regained the ascendency in the 64th minute when Kai Ishii sprinted over following another period of sustained pressure.

However, it did not last long as Nakamura converted his own try -- slightly controversial as there seemed to be a hint of crossing in the buildup -- to make it 23-17 with nine minutes remaining on the clock.

But the drama was only just unfolding as Shohei Toyoshima made the most of a sublime pass from Stephen Donald to dive over in the corner, with van Wyk again on target from out wide.

Knowing they needed to get a bonus point if they were to have any chance of overtaking Verblitz, Toshiba continued with their high-risk approach. But it backfired as Australia and Suntory back-row forward Sean McMahon closed the game out by scoring his second TL try in as many games to ensure it was the yellow half of the Tokyo suburb of Fuchu that spent Christmas Eve celebrating.

"That was a good performance from the new starting members and from the bench," said Suntory coach Keisuke Sawaki, adding he thought the standard of play at the breakdown was of a very high standard.