London Irish missed the chance to move top of the Guinness Premiership after they were held 16-16 at home to Worcester on Saturday.
A fortnight after losing their unbeaten home record to Newcastle, the Exiles were again troubled with Willie Walker kicking eleven points for the visitors, who were awarded a penalty try.
John Rudd scored the hosts' only try, while Ryan Lamb converted and kicked three penalties.
The match began with a couple of bouts of niggle between the opposing packs.
Referee Tim Wigglesworth decided to send Worcester's Kiwi lock Greg Rawlinson to the sin-bin to calm things down, but Irish could not take advantage of the extra man.
Exiles fly-half Lamb, fresh from a match-winning performance at Bath last week, mounted the first threat to either line with a clever snipe but his floated pass failed to reach unmarked wing Peter Hewat.
Shortly afterwards the former Gloucester number 10 missed a straight-forward penalty chance.
With Rawlinson poised to return, Worcester's 14 men opened the scoring with a Willie Walker penalty, after Irish infringed at a ruck.
Walker doubled the advantage early in the second quarter, after Irish again fell foul of the referee at the breakdown, to bring up his personal century of Premiership points this season.
Tepid Irish roused themselves at last just before the half-hour and Worcester flanker Tom Wood was sent to the cooler after a blatant high tackle.
Lamb this time knocked over the kick, but his score was almost immediately cancelled out by a superb Walker effort from the touchline following yet more Irish indiscipline.
The Exiles had their first spell of sustained pressure just before the break. England scrum-half Paul Hodgson, selected on the bench but on for the injured Peter Richards, failed with a quick tap in the shadow of the Worcester posts but Irish ended a scrappy half by taking the three points on offer from an identical position to trail 6-9.
Irish went ahead for the first time early in the second period.
Wing Rudd cut a superb line through the drifting Worcester defence midway inside the Warriors half and slid under the posts.
Lamb converted but, rather than kick-starting the Irish effort, the visitors bounced back immediately, pinning Irish on their line and forcing a penalty try when referee Wigglesworth spotted handling in a five-metre scrum.
It was Worcester's first try in almost five hours of Premiership rugby. Walker slotted the simple conversion to give his side a three-point lead.
The Exiles were turned over on the brink of the Worcester line, but Lamb's third penalty levelled the scores just past the hour.
Irish pinned the visitors in their own half but their error count remained high and they were fortunate not to slip behind when Walker missed from a shot at goal from 25 metres.
The majority of the final 10 minutes was played out in the Warriors' half but Irish failed to threaten a side who have still to post a league win away from Sixways this campaign.
For London Irish:
Pen: Lamb 3
Pen: Walker 3
London Irish: 15 Jamie Lennard, 14 Peter Hewat, 13 Elvis Seveali'i, 12 Seilala Mapusua, 11 John Rudd, 10 Ryan Lamb, 9 Peter Richards, 8 Chris Hala'Ufia, 7 Steffon Armitage, 6 Richard Thorpe, 5 Bob Casey (c), 4 Nick Kennedy, 3 Paulica Ion, 2 David Paice, 1 Dan Murphy.
Replacements: 16 Danie Coetzee, 17 Clarke Dermody, 18 Alex Corbisiero, 19 Kieran Roche, 20 Jonathon Fisher, 21 Tom Homer, 22 Paul Hodgson, 23 Chris Malone.
Worcester: 15 Chris Latham, 14 Rico Gear, 13 Dale Rasmussen, 12 Sam Tuitupou, 11 Miles Benjamin, 10 Willie Walker, 9 Jonny Arr, 8 Kai Horstmann, 7 Pat Sanderson (c), 6 Tom Wood, 5 Craig Gillies, 4 Greg Rawlinson, 3 Tevita Taumoepeau, 2 Aleki Lutui, 1 Adam Black.
Replacements: 16 Jack Gilding, 17 Chris Fortey, 18 Olivier Sourgens, 19 Will Bowley, 20 James Collins, 21 Ollie Frost, 22 Calum MacRae, 23 Alex Grove.
Referee: Tim Wigglesworth
Assistant referees: Alan Biggs, Andrew Watson
Coach: Ashley Reay
Television match official: Brian Abrahams