Old boy Masoe sinks Toulon
Masoe, who left Toulon recently after three years, grabbed his side's decisive try late in the second period when they were trailing 19-17.
Both sides went into the season curtain-raiser stripped of a host of stars who are building up for next month's World Cup – Toulon were missing 18 players and Racing 11.
"When you look at our resources before the game, we knew it would be difficult, but we cannot hide behind that," said Toulon boss Bernard Laporte.
"We need experienced players to become leaders."
Racing manager Laurent Labit, who will welcome All Blacks star flyhalf Dan Carter after the World Cup, hailed his team's fighting spirit after they were twice reduced to 14 men.
"We wanted to forge a collective mindset that had been lacking last season," he explained of a side who were defeated in the quarterfinals last season.
"The contribution of our young players was very important. They brought a certain freshness, a certain enthusiasm."
Jonathan Pelissie, who was to score 19 of Toulon's points, kicked two early penalties to Racing's one through Maxime Machenaud.
Racing were reduced to 14 men when No.8 Antonie Claasen was sin-binned for a dangerous tackle on English fullback Delon Armitage.
Toulon pressed home their advantage when Pelissie, set-up by a smart burst from skipper Juan Smith, went over for the season's first try under the posts.
The scrumhalf kicked the extras for a 13-3 lead.
Machenaud and Pelissie again exchanged penalties before Racing scored their first try on the stroke of half-time through centre Henry Chavancy.
Machenaud missed the conversion and Toulon went in at the break 16-11 to the good.
The Racing scrumhalf added two quick penalties after the interval to nudge his side into a 17-16 lead before their fightback was thwarted by a second yellow card of the evening.
This time it was South African lock forward Francois van der Merwe who was the culprit when he was sin-binned for a rash punch at the prone Thibaut Lassale.
Pelissie compounded Racing's indiscipline with another penalty for a 19-17 lead.
Racing lost flyhalf Johan Goosen to a shoulder injury just after an hour before Australian centre Mitch Inman, making his Toulon debut, was yellow carded in the 65th minute for repeated indiscretions.
Racing pounced with a mighty shove as flanker Masoe, who left Toulon after the conclusion of last season, was driven over for his side's second try of the game.
Mechanaud added the extras for 24-19 which soon became 27-19 when he popped over a penalty after a weary Toulon front row were penalised for collapsing a scrum.
Pelissie then hit a penalty wide of the posts with three minutes left before replacement fly-half Willie du Plessis succeeded with another as the clock ticked down to at least ensure the European champions a losing bonus point.
AFP