Gloucester firmly answered their Guinness Premiership critics by recording a resounding 34-14 win over London Irish at Kingsholm on Saturday.
Bath had temporarily held top spot following their early victory over Newcastle, but Dean Ryan's side claimed a try bonus point as they moved four points clear at the summit.
The result also ended London Irish's run of five successive wins in the competition.
Gloucester head coach Dean Ryan gave a debut to Irish lock Dan Tuohy and included young backs Charlie Sharples and Dan Norton on the bench.
The Exiles had Argentina international Juan Leguizamon back at blindside flanker and former All Black Clarke Dermody on the replacements bench.
With Paul Hodgson on England duty, Warren Fury started at scrum-half - with midweek signing Ross Blake, the Cambridge University number nine, among the replacements.
In driving rain, the visitors missed early chances with full-back Peter Hewat off target with a penalty from 30 metres.
Gloucester were quickly up the other end, and a neat grubber kick fell for prop Nick Wood to plough through and touch down close to the posts.
A second try followed as full-back James Bailey broke down the right, before kicking ahead. Centre Jack Adams capitalised as the Exiles made a mess of collecting the loose ball, winning the race for the score.
Fly-half Willie Walker added the simple conversions to both tries before Hewat found his range with a 20-metre penalty midway through the half.
The London Irish defence was again exposed as left wing Mark Foster collected a kick ahead from Tuohy before racing through to touch down by the posts - and Walker added the extras.
With five minutes of the half remaining, Gloucester hooker Andy Titterrell was at the centre of a tussle on the ground.
When referee David Rose restored order, by speaking to the players involved and the two captains, he awarded Gloucester a penalty - which Walker slotted between the uprights.
Titterrell had to leave the field for treatment, and his replacement Olivier Azam was soon sent to the sin-bin for foul play.
Hewat kicked the resultant penalty, but Gloucester led nonetheless 24-6 at the break.
The visitors started the second-half the stronger up against fourteen men and continued to dominate when Gloucester were back to full strength - Hewat landing his third penalty from in front of the posts.
London Irish then reduced the arrears further as wing Topsy Ojo intercepted a pass fifteen metres inside his own half before outpacing two Gloucester players to touch down - but Hewat was off target with his conversion attempt.
Walker had a similar problem with his next penalty kick but then found the mark midway through the half.
However, nothing seemed to be going for the Exiles - and with five minutes remaining, David Paice was sent to the sin-bin for repeated offences.
And Gloucester made the most of their extra man, driving the visitors back over their own line with a shove from their depleted pack.
Referee Rose consulted the television match official Graham Hughes before awarding the bonus-point try with Titterrell the last man to his feet.
Tries: Wood, Adams, Foster, Titterrell
Con: Walker 4
Pen: Walker 2
For London Irish:
Pen: Hewat 3
Gloucester: 15 James Bailey, 14 James Simpson-Daniel, 13 Jack Adams, 12 Anthony Allen, 11 Mark Foster, 10 Willie Walker, 9 Gareth Cooper, 8 Akapusi Qera, 7 Andy Hazell, 6 Peter Buxton (c), 5 Dan Tuohy, 4 Will James, 3 Jack Forster, 2 Andy Titterrell, 1 Nick Wood.
Replacements: 16 Olivier Azam 17 Christian Califano 18 Jonathan Pendlebury 19 Jeremy Paul 20 Mike Prendergast 21 Charlie Sharples 22 Dan Norton.
London Irish: 15 Peter Hewat, 14 Topsy Ojo, 13 GonzaloTiesi, 12 Seilala Mapusua, 11 Sailosi Tagicakibau, 10 Mike Catt, 9 Warren Fury, 8 Richard Thorpe, 7 Steffon Armitage, 6 Juan Leguizamon, 5 Bob Casey (c), 4 Kieran Roche, 3 Faan Rautenbach, 2 David Paice, 1 Dan Murphy.
Replacements: 16 Clarke Dermody, 17 Stuart Mackie, 18 Tonga Lea'aetoa, 19 Gary Johnson, 20 Declan Danaher, 21 Ross Blake, 22 Eoghan Hickey.
Referee: David Rose
Touch judges: Stuart Terheege, Kevin Stewart
Television match official: Bob Ockenden, Graham Hughes