Sean McMahon made his Top League debut eight months earlier than expected, hitting the ground running with Suntory.
McMahon was originally meant to link up with the team in April next year, before an August season start, but was called in to join the reigning champions last weekend, with veteran Wallabies flanker George Smith suffering a long-term back injury.
The 23-year-old impressed in his first Japanese foray, a 24-7 win over Kobe, playing alongside 2015 World Cup teammate Matt Giteau, scoring a try just 13 minutes into his debut.
McMahon told Japanese news outlet Kyodo news he was still adjusting to a new style of rugby.
"They gave me a call and I just hope I can help them finish the year on a high,” he said.
"That was a lot quicker than I expected and was very physical as well.
"Kobe are an exceptional side. But once I found my feet I had a couple of good ball carries. But I need to work on my game."
Adam Ashley-Cooper was at 13 for Kobe in the match.
Former Reds back Campbell Magnay came off the bench for Suntory for the final 20 minutes of McMahon’s debut.
Suntory’s biggest rival for the title this year, Panasonic, had a huge 50-7 win over Ricoh, led by former Wallaby Berrick Barnes.
Barnes had 10 points off the boot, while two- Test Wallabies lock Daniel Heenan opened the Wild Knights’ scores with a try just five minutes into the clash.
David Pocock played 66 minutes for Panasonic in the clash, starting at openside.
Canon 20 - NEC Green Rockets 25
Yamaha 40 - Munakata Sanix Blues 5
NTT Docomo Red Hurricanes 38 - Toyota Industries Shuttles 19
Toyota Verblitz 22 - NTT Shining Arcs 15
Coca-Cola Red Sparks 5 - Kubota Spears 12
Suntory 24 - Kobe Steelers 7
Toshiba Brave Lupus 51 - Kintetsu Liners 14
Panasonic 50 - Ricoh Black Rams 7
Christian Lealiifano starred for Ulster as the Irish side cruised to a big win on their home ground against Harlequins.
Lealifano was named man-of-the-match, growing in strength each week in his short-term stint with his new team.
Former Brumbies fullback Jesse Mogg was in action in a Montpellier victory over Glasgow, keeping their knockout hopes alive.
Scott Fardy was at lock for Leinster in a grinding win over Exeter, 22-17, against his former Brumbies teammate Nic White, who started at nine for the Chiefs alongside Lachie Turner, at fullback.
Will Skelton was yellow-carded as Saracens were condemned to their second European defeat to Clermont in six days.
Skelton was binned for repeated infringements as the London side slumped to their seventh straight defeat, against former Waratahs teammate Peter Betham’s side.
Ben Tapuai started at 12 for Bath in a tense win over Toulon, while former Aussie Sevens star Nick Malouf came off the bench for Leicester in their loss to Munster.
Ulster 52 - Harlequins 24
Montpellier 36 - Glasgow 26
Benetton 12 - Scarlets 31
Leinster 22 - Exeter 17
Racing 29 - Castres 7
Bath 26 - Toulon 21
Wasps 21 - La Rochelle 3
Ospreys 31 - Northampton 15
Clermont 24 - Saracens 21
Leicester 16 - Munster 25
Mike Harris steered Lyon in a 21- 11 win over Toulouse, putting them on top of their Challenge Cup pool, midway through the competition.
Pau 26 - Agen 12
Dragons 25 - Newcastle 27
Edinburgh 78 - Krasny Yar 0
Oyonnax 27 - Worcester 20
Bordeaux 36 - Enisei-STM 27
Gloucester 69 - Zebre 12
London Irish 20 - Stade Francais 26
Connacht 55 - Brive 10
Lyon 21 - Toulouse 11
Cardiff 14 - Sale 6