Finn Russell kicked 12 points to guide the Glasgow Warriors to a 17-0 win over Edinburgh, while there were also Pro14 wins for Treviso, the Scarlets and Ospreys.
In a substandard first half, Russell landed a penalty as the Warriors took a 3-0 lead. But the first half came to an abrupt end when Scotstoun Stadium had to be evacuated due to a fire alarm being set off. After a 20-minute delay, play resumed with the start of the second half after match officials decided to abandon the last two minutes of the first half.
Unflustered by the disruption, Russell succeeded with three more penalty kicks for a 12-0 lead before wing Lee Jones went over for Glasgow’s first try late in the game.
In the only other match on Saturday, flyhalf Marty Banks contributed eight points via a conversion and two penalties to guide Treviso to a 20-16 win against Italian rivals Zebre.
On Sunday, the Scarlets extended their lead at the top of Conference B after edging the Cardiff Blues 14-11, while the Ospreys claimed a much-needed win as they downed the Dragons 22-9.
Round 12 results:
Zebre 16 Treviso 20
Leinster vs Connacht (17:15)
Ulster vs Munster (19:35)