Pressure mounts on Matt O'Connor as Leinster lose to Ulster
Ulster 26 Leinster 10
Leaders Ulster ensured their place in the Guinness PRO12 top four with a rare but highly-prized 26-10 victory over Leinster at a damp Kingspan Stadium which keeps the home side on target for a home semi-final.
This defeat for Leinster comes on the back of last weekend's Champions Cup defeat against Toulon to heap more pressure on coach Matt O'Connor.
Tries in each half from man of the match Iain Henderson and the PRO12's leading try scorer Craig Gilroy helped secure the result - which took Ulster top of the table overnight - which all but ends Leinster's hopes of making the top four.
Four penalties from Ruan Pienaar, who also converted both tries, also contributed to the result while Leinster - who were undoubtedly weary five days on from their Champions Cup exit - scored a try from Ben Te'o along with a conversion and penalty from Jimmy Gopperth.
Ulster led 13-10 at half-time and put the pressure on in the second period to take it beyond the visitors, who had no reply in the latter 40 minutes.
Leinster, though, made the best possible start by taking play deep into Ulster territory and coming away with an early penalty strike from Gopperth.
And after six minutes, things got even better for the visitors as they sought to rescue their already brittle-looking play-off hopes, when Te'o smashed through some weak first-up tackling to score. Gopperth added the extras and Leinster were 10-0 to the good and looking comfortable.
Ulster needed to respond and after Pienaar's opening long-range penalty fell short, they got over the line with Henderson storming over. Pienaar converted his 12th-minute effort and then added a penalty shortly afterwards to tie the scores.
There then followed a moment of controversy after Henderson was tip-tackled by Sean O'Brien with referee John Lacey and the TMO opting for a yellow card for the Ireland flanker instead of the red one the home crowed were baying for.
Ulster, though, failed to score during O'Brien's absence - Pienaar was wide with a long-range penalty - but did manage to finish the half by dominating territory and they got their just reward when Pienaar kicked a 37th-minute three-pointer to give the home side the lead for the first time.
As the tension rose in a scrappy second half, Paddy Jackson's chip saw Gilroy gather and touch down but, courtesy of the TMO, it looked clear that Rob Kearney's hit had forced the winger into touch.
Ulster then got a lucky break with Louis Ludik somehow scything through. Tommy Bowe got on the end of Ludik's pass and was held up short which saw Pienaar then cross-kick for Gilroy who was again put into touch.
But play was called back by referee Lacey and Kearney was sin-binned giving Pienaar a 63rd-minute penalty which he duly slotted to stretch the lead to 16-10.
Three minutes later the South African nailed a monster effort from just inside Leinster's half and the home side now had a considerable comfort blanket.
It already looked too late for Leinster and their humiliation was completed with eight minutes remaining when a huge Ulster power play off a scrum on Leinster's line ultimately saw Gilroy dance through for his 11th PRO12 try of the campaign.
Pienaar converted to make it 26-10 and the game ended with 14-man Ulster - replacement prop Andy Warwick had been binned - defending their line as if their lives depended on it.