Heineken Cup: Pool 4:Munster 36 Castres 8, Thomond ParkScorers: Munster: Tries: Foley, Leamy, O'Connell, Sheahan, Cullen; Cons: O'Gara 3, Burke; Pen: O'Gara
Ronan O'Gara - who had notched all but five of Munster's points in their previous two games - became the Heineken Cup's leading scorer on 649 points as Alan Gaffney's side powered to the summit of Pool 4.
The 27-year-old converted first half tries from skipper Anthony Foley and young flanker Denis Leamy, in what turned out to be a 50-minute opening period.
He tagged on the extras to Paul O'Connell's left wing try on 49 minutes, before ending his 50th European cap with a yellow card - following an off-the-ball altercation with former Ulster prop Justin Fitzpatrick.
Gaffney made three changes from the side which lost 19-12 in France last Friday, but his charges began poorly.
O'Gara missed a lengthy first shot at goal and lock Donncha O'Callaghan was sin-binned for a ruck punch inside the first six minutes.
Castres full-back Ugo Mola then created the space for Castres' only try, exposing Munster's midfield defence before unleashing right wing Benjamin Lhande to ghost over unopposed from 25 metres out.
Laurent Marticorena pulled the conversion wide from the left flank, but the try alone was enough to spark heat from Munster.
An altercation between Peter Stringer and Castres lock Lionel Nallet on 17 minutes led to a midfield melee but English referee Roy Maybank kept his card firmly in his pocket.
Six minutes later, captain Foley took a quick tap to barge over past meek tackles from Romain Froment and Mola to see the home side back level.
O'Gara's conversion was cancelled out by Marticorena's penalty on 29 minutes, but with Argentina international Mauricio Reggiardo off the field for a kicking offence on Foley, Munster's bulldozing maul saw them retake the lead.
The way was cleared then seven minutes into injury time for Leamy to bag his second European try.
After repeated pops at the French line, hooker Sheahan's five-metre throw was taken by O'Connell, neatly recycled by Foley and lunged over by Leamy, under the challenge of Fitzpatrick.
O'Gara converted and in kicking a second penalty in the 10th added minute, became Europe's highest ever scorer, edging clear of Diego Dominguez's mark of 645.
Leading 17-8, O'Connell gave Munster the perfect start to the second half, fending off both Alexandre Albouy and Paul Volley to stretch his 6ft 6in frame over in the left corner.
O'Gara clawed the touchline extras brilliantly over and Castres' woes were compounded when close-in lineout drive saw hooker Frankie Sheahan muscle over on 68 minutes for the bonus point.
By that stage, O'Gara had been yellow-carded for a confrontation with Fitzpatrick, but Munster rounded off their night in style, with ex-All Black Christian Cullen racing through for his first European try on 80 minutes.
Referee Maybank also red-carded Castres tighthead prop Alessio Galasso for yet more punching, as the visitors' challenge waned.
(15) Christian Cullen(14) Shaun Payne(13) Mike Mullins(12) Rob Henderson(11) Anthony Horgan(10) Ronan O'Gara(9) Peter Stringer(1) Marcus Horan(2) Frank Sheahan(3) John Hayes(4) Donncha O'Callaghan(5) Paul O'Connell(6) Alan Quinlan
Replacements used: Paul Burke for Quinlan (70 mins), Jim Williams for O'Gara (76), Gordon McIlwham for Horan (81), Mike Prendergast for Stringer (82), Mossy Lawlor for Horgan (86). Not used: James Blaney, Trevor Hogan.
Heineken Cup: Pool 6:Ulster 18 Stade Francais 10, RavenhillScorers: Ulster: Tries: Campbell, Humphreys; Con: Humphreys; Pen: Humphreys: Drop gl: Humphreys
Ireland's record points scorer David Humphreys put in another virtuoso performance as he scored a try, a conversion, a penalty and drop goal as Ulster got their Pool 6 tilt back on track.
The 33-year-old, who carried a toe injury into the game, scored 13 of Ulster's points as they avenged last Saturday's 30-10 loss at Stade.
A superb individual try from scrum-half Kieran Campbell saw Mark McCall's side on their way late in the first half.
Two minutes in, they looked a long way off recording their third home win of the season. With Agustin Pichot immediately causing trouble around the fringes, Stade had Ulster on the back foot and had acres of space when Pichot fed David Skrela.
The Stade fly-half put in a kick behind the cover and full-back Juan-Martin Hernandez advanced easily to touch down. Skrela also converted.
Humphreys narrowed the score with a ninth minute penalty and then Skrela missed a 13th-minute effort when his attempt bounced out off the upright.
On the half hour, Mirco Bergamasco got on the end of a kick and chase for 50 metres but just failed to get the touchdown as the ball rolled dead.
Humphreys was short with a 50-metre penalty effort on 40 minutes before, out of nowhere, Ulster grabbed an injury-time try. Campbell ran a penalty and just kept going, beating three Stade defenders to slide over to the left of the posts.
Humphreys missed the conversion for an 8-7 half-time lead, but soon after the restart, Skrela drew Stade back in front with a well-taken drop goal.
On 62 minutes, Ulster struck for a decisive second try. The ball was recycled right, and Humphreys was put in space on the wing. He made the corner and then added a superb conversion to take it to 15-10 for the home side.
A third drop goal of the European campaign from Humphreys deservedly saw McCall's charges to victory, moving the northerners five points behind second-placed Gloucester, and six back from pace setters Stade.
Ulster face two must-win games, when entertaining Gloucester at Ravenhill on January 8, while a week later, they travel to the winless Cardiff Blues.
(15) Bryn Cunningham(14) Scott Young(13) Jonny Bell(12) Kevin Maggs(11) Tommy Bowe(10) David Humphreys(9) Kieran Campbell(1) Ronan McCormack(2) Paul Shields(3) Rod Moore(4) Gary Longwell(5) Matt McCullough(6) Campbell Feather (Capt)(7) Neil Best(8) Roger Wilson
Replacements used: Paul Steinmetz for S Young (26 mins), Rowan Frost for Longwell (79), Bryan Young for McCormack (81). Not used: Nigel Brady, Matt Mustchin, Neil Doak, Adam Larkin.