A superb solo try from Craig Gilroy sparked a second-half fight-back from Ulster against Scarlets at Kingspan Stadium.
Luke Marshall and Ruan Pienaar also crossed for tries to help them to a 25-20 victory, with Pienaar notching 15 points in total.
The result means that Ulster have now moved level on points with league leaders Glasgow, who travel to Cork to face Munster tomorrow.
Leinster's Jimmy Gopperth kicks a penalty ©INPHO/Craig Thomas
Meanwhile, Leinster battled their way to a draw against the Ospreys at the Liberty Stadium.
Three penalties from Jimmy Gopperth, including a late effort to bring his side level, helped Leinster to snatch a 9-9 draw.
The result helps Leinster to move up to third place in the table, at least temporarily, and crucially it keeps them ahead of the Ospreys in the battle for a top-four finish.
