Toulon cling on to edge Montpellier, Clermont climb to 5th
In a match postponed on Saturday because of the weather conditions on the Mediterranean coast, Domon scored a try and kicked three penalties and as many conversions for a 20-point personal haul.
His penalty gave the home side an early lead but they were soon trailing when Montpellier prop Wilfrid Hounkpatin crashed over after nine minutes.
Just before the half-hour, hooker Christopher Tolofua, who joined Montpellier from Toulon in 2024, went over for a second try.
Toulon hit back just before half-time with a try by wing Gael Drean -- his eighth of the season -- to turn around just one point adrift at 16-17.
A quickly-taken penalty close to the line eight minutes after the restart gave Domon the opening for a try which put Toulon ahead.
The full-back then converted a third Toulon try from Georgian prop Beka Gigashvili.
Jordan Uelese's try 11 minutes from time meant a close finish and although Montpellier could not eke out the win, they did take home a losing bonus point, although they dropped to seventh in the table.
New Zealand international Harry Plummer starred as Clermont ran in four tries against an ill-disciplined La Rochelle in the Massif Central.
Fiji flanker Levani Botia's try had helped the visitors into a 10-3 lead but his sin-binning for collapsing a maul, which resulted in Clermont being awarded a penalty try, turned the game in the hosts' favour.
Plummer went over under the posts and wing Joris Jurand collected his own chip to score a third try for Clermont.
Another yellow card for Judicael Cancoriet in the second half looked to have ended La Rochelle's hopes of a comeback, particularly as No.8 Selevasio Tolofua added a fourth Clermont try to open up a 32-10 lead.
But fly-half Antoine Hastoy and No.8 Gregory Alldritt, who was dropped from France coach Fabien Galthie's Six Nations squad in midweek, pulled La Rochelle back into contention.
And when flanker Anthime Hemery was sin-binned 11 minutes form the end, Clermont looked to be in trouble but La Rochelle could only add an Ihaia West penalty to earn a losing bonus point.
On Saturday, France captain Antoine Dupont provided two assists but was yellow carded as leaders Toulouse strolled past second-placed Pau 59-22 to move six points clear at the top of the table.