Machenaud, Racing end Clermont's winning streak
Machenaud racked up 21 points with the boot while Albert Vulivuli added a late try to give European Cup finalists Racing some breathing space late on at the Stade Yves-du-Manoir.
Aurelien Rougerie and Damien Chouly both crossed in the first half for Clermont, but the visitors were held to a pair of penalties – one apiece from Morgan Parra and Camille Lopez – after the interval.
Racing moved level on points with third-place Toulon, while Clermont's lead at the top was trimmed to two points after Montpellier thrashed Grenoble 51-10 on Saturday.
Racing were without All Blacks superstar Dan Carter who had sparked a degree of alarm amongst fans when he was pictured on social media using a crutch.
However, the 34-year-old, who was hurt in Racing's defeat of Leicester in last weekend's European Cup semifinals, insisted his calf injury was nothing serious.
Clermont knew a win in the capital would edge them closer to a semifinal place in the end-of-season play-offs and the visitors struck first when Wesley Fofana fed Rougerie and the former France centre charged through the Racing defence, with Parra converting.
But Racing responded with three penalties from Machenaud to take a 9-7 lead while Clermont were reduced to 14 with Alexandre Lapandry sin-binned for tackling an opponent without the ball.
Franck Azema's men added a superb second try on 36 minutes as Chouly and Nick Abendanon combined out on the left wing to send the former bursting through, Parra again slotting over the conversion.
Machenaud landed his fourth penalty of the half to reduce the deficit to 14-12 at the break, but Parra booted through a long-range penalty to keep Clermont in control.
Machenaud again trimmed the gap to two and Clermont once more found themselves a man down after replacement Jonathan Davies was yellow-carded having come on for Rougerie.
Machenaud then delivered to put Racing on top 18-17 and although Lopez hit back moments later, the Racing scrumhalf put the hosts ahead for good with his seventh penalty of the afternoon.
Lopez dragged wide as Clermont missed a chance to wrest back the advantage, and Vulivuli ensured Racing completed the double over their opponents this season when he picked up a loose ball after Davies' kick was charged down by Joe Rokocoko.
Round 22 results:
Racing 26 Clermont 20
Toulon 10 Toulouse 12
Castres 37 Pau 6
Agen 37 Brive 19
Montpellier 51 Grenoble 10
Oyonnax 17 La Rochelle 16
Bordeaux-Begles 35 Stade Francais 25
Agence France-Presse
