Callum Black crashed over the try line on his 100th Ulster appearance as the hosts saw off Glasgow Warriors 13-10 at the Kingspan Stadium.
Despite the visitors going ahead early through Lee Jones' first GUINNESS PRO12 try of the season, in-form Ulster slowly battled back with Black's converted second-half try opening up some breathing space.
Penalties for Ruan Pienaar and Paddy Jackson also kept the hosts in the driving seat and while Taqele Naiyaravoro got a late consolation to earn Glasgow a losing bonus point, Ulster still extended their recent run to just one loss in their last six GUINNESS PRO12 fixtures.
Ulster started off on the front foot and had an early chance to opening the scoring on six minutes when they were awarded a penalty within range of the posts.
But Pienaar, attempting his first kick of the 2015/2016 GUINNESS PRO12 season, miscued his effort and the ball sailed wide.
Three minutes later and the first points of the game did arrive though, this time for visitors Glasgow after some superb play for their young backline.
Winning the line out on the far touch line, the visitors eventually went for the catch and drive before quick hands released centre Johnson to burst through the Ulster defence with a darting line.
He was able to release the ball and it was eventually fed out to the near touchline where Jones was able to dart over for a 5-0 lead - Gregor Hunter off target with the conversion.
Ulster looked to hit back, and when they turned over the ball in midfield, a clever pass played in Alan O'Connor to make up some ground.
The ball was eventually lost, but with referee Marius Mitrea playing advantage for an earlier offside, Pienaar dutifully stepped up to add a simple three points.
The momentum was now with the hosts and Gilroy was again the driving factor, picking the ball up on the halfway line before eyeing a space down the right.
With options limited, he opted to kick forward with Pienaar in pursuit but Ali Price just won the footrace before the line as Ulster had to settle for a five metre scrum.
Despite repeatedly pushing for the try line the Glasgow defence however stood firm and eventually won a penalty of their own to relieve the pressure.
The hosts thought they had notched a try just past the half hour mark when Paul Marshall seized on a loose ball but the TMO ruled there had been no downward pressure as they scores remained 5-3 in Glasgow's favour at the break.
Glasgow looked to begin the second-half strongly and were awarded a penalty with Hunter opting to kick for the posts from over 40m but his effort flew wide on 48 minutes.
And just five minutes later Ulster hit back as a trademark darting run from Gilroy pulled his side towards Glasgow's line with Black eventually crashing over. Jackson added the conversion and the hosts were 10-5 up.
The Kingspan Stadium was now rocking and they were given another reason to cheer when Jacob Stockdale gathered a deep kick before gathering his own chip forward and cantering upfield before eventually being stopped, while the Warriors defence held firm against another Ulster attack.
The penalties were starting to add up for Glasgow now though and Jackson took advantage of another one to take the score to 13-5.
Another error from Glasgow resulted in Ryan Wilson receiving a yellow on 70 minutes for pulling down the line-out.
To their credit, the visitors refused to let their heads drop and they earned what could be a crucial losing bonus point come the end of the season when Naiyaravoro crashed over but Ulster went back to the top of the table.
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