Stephen Betham (Gallo)
London - After opening Rugby World Cup victories, Japan and Samoa were given reality checks in defeat last time out and their quarter-final hopes will be on the line when they meet in Milton Keynes on Saturday.
Japan's euphoria at stunning South Africa was checked when they went down to Scotland four days later, while Samoa saw off the United States only to then feel the full force of a Springboks backlash.
Samoa and Japan, ranked 11 and 12 in the world respectively, have four points from two matches in Pool B, three behind South Africa and six behind the Scots. Defeat for either in Milton Keynes will deal a major blow to their chances of reaching the knockout stage.
Both sides are feeling the pressure.
"Our backs are against the wall now and it will be all hands on deck for this game against Japan," Samoa coach Stephen Betham said.
The Samoans kept it tight against South Africa for 15 minutes but their heads dropped after JP Pietersen's interception try, the first of three for the Springbok winger in a 46-6 rout.
"We're treating it like a World Cup final in our eyes. Japan are not to be taken likely," said Samoa centre George Pisi, whose brother Tusu Pisi needs 17 points to overtake Earl Va'a (174) as Samoa's highest-scoring test player.
Samoa have made five changes to the line-up that started against South Africa, with Johnny Leota, Tusi Pisi, Fafili Levave, Kane Thompson and Ole Avei coming in.
Lock Thompson has served his two-match ban for striking Saia Fainga'a in Samoa's match against the Barbarians in late August.
Japan appeared jaded in the second half of their 45-10 defeat by Scotland. Coach Eddie Jones refused to blame fatigue for the loss but will not be unhappy that they have now had time to recover after their hectic start to the tournament.
While Japan are braced for a physical battle with the combative Samoans, the Brave Blossoms believe they have the attacking threat to put points on the board.
Jones has made five changes to the team that lost to Scotland.
Kensuke Hatakeyama replaces Hiroshi Yamashita at tighthead prop, lock Hitoshi Ono is in for Justin Ives while Kosei Ono comes in at flyhalf, with Harumichi Tatekawa moving to inside centre.
Kotaro Matsushima switches wings to accommodate Akihito Yamada at the expense of Kenki Fukuoka.
1 Sakaria Taulafo, 2 Ole Avei, 3 Census Johnston, 4 Teofilo Paulo, 5 Kane Thompson, 6 Ofisa Treviranus (captain), 7 TJ Ioane, 8 Faifili Levave; 9 Kahn Fotuali'i, 10 Tusi Pisi, 11 Alesana Tuilagi, 12 Johnny Leota, 13 Paul Perez, 14 Ken Pisi 15 Tim Nanai-Williams
Replacements: 16 Motu Matu'u, 17 Viliamu Afatia, 18 Anthony Perenise, 19 Jack Lam, 20 Vavae Tuilagi, 21 Vavao Afemai, 22 Mike Stanley, 23 Rey Lee-Lo
1 Keita Inagaki, 2 Shota Horie, 3 Kensuke Hatakeyama, 4 Luke Thompson, 5 Hitoshi Ono, 6 Michael Leitch (captain), 7 Michael Broadhurst, 8 Ryu Koliniasi Holani, 9 Fumiaki Tanaka, 10 Kosei Ono, 11 Kotaro Matsushima, 12 Harumichi Tatekawa, 13 Male Sau, 14 Akihito Yamada, 15 Ayumu Goromaru
Replacements: 16 Takeshi Kizu, 17 Masataka Mikami, 18 Hiroshi Yamashita, 19 Justin Ives, 20 Amanaki Mafi, 21 Hendrik Tui, 22 Atsushi Hiwasa, 23 Karne Hesketh
Referee: Craig Joubert (South Africa)