Panasonic Wild Knights head into the five-week autumn break as the only unbeaten team in the Japan Rugby Top League following a 21-10 win over Suntory Sungoliath on Saturday.

In an absorbing, physical game at Kumagaya Athletic Stadium, Robbie Deans' team may have seen their perfect start to the season come to an end -- they failed to get a bonus point for scoring three or more tries than their opponent -- but they ended Suntory's long unbeaten run.

Keisuke Sawaki's side had not lost in the league since Dec. 26, 2015, and the defending champions will be hoping to get a shot at revenge come the playoffs.

This season the league has been split into two conferences.

Teams play the seven other sides in their conference plus six from the other group to determine the rankings for the end of season playoffs, with the top four sides competing for the league title, which doubles as the All-Japan Championship.

 Rugby: Panasonic end Suntory's long unbeaten run

Akihito Yamada's 10th try of the season eventually proved to be the killer blow as Panasonic made it 44 points from a possible 45 in the White Conference, while Suntory lead the Red Conference with 38 points.

Yamaha are second in the White Conference with 35 points following their 35-5 win over Kubota Spears, while Toyota Verblitz (28 points) trail the Red group's second-placed team Kobe Kobelco Steelers, who play Ricoh Black Rams on Sunday, on points difference.

Rugby World Cup 2007 winner Juan Smith was handed the Verblitz captaincy to mark his final game of rugby before heading into retirement and his teammates made sure he went out on a winning note as they beat Toyota Industries Shuttles 33-24.

In the day's other games, NTT Communications Shining Arcs ensured Coca-Cola Red Sparks remain the league's only winless side as they ran in 10 tries, and got a penalty try for good measure, in a 76-7 thrashing. Toshiba Brave Lupus came from behind to beat Munakata Sanix Blues 34-20, while NEC Green Rockets downed Kintetsu Liners 17-10.

The game in Kumagaya got off to a sensational start with Kenki Fukuoka sprinting over within 30 seconds of the opening whistle as the Wild Knights regathered their own kickoff and then ran the ball from side to side to provide the flying wing the opportunity to go over.

A pair of tries from Suntory speedster Chihito Matsui, both set up by Hendrik Tui, either side of a penalty from Berrick Barnes saw Suntory go 10-8 up.

A penalty from Rikiya Matsuda, however, gave the Wild Knights the lead just before the break.

With neither defense giving an inch -- props Keita Inagaki and Asaeli Ai Valu were particularly prominent for Panasonic -- the second stanza was just as tight.

"One point to today's game was our being able to defend without giving them anything," Panasonic captain Shunsuke Nunomaki said.

Yamada eventually broke the deadlock in the 61st minute following some great work in the tackle by Matsuda, who added the extras and then a penalty 10 minutes later.

Suntory did their best to close the gap but with man-of-the-match David Pocock showing why he is regarded as one of the best flankers of all time, the Wild Knights forced turnovers at crucial moments and held on for the win.