Knocked to the ground by the blast, a bible in Armenian script lay open on the floor, covered in dust.
Sun passing through a hole in the roof lit a scene of devastation.
The Ghazanchetsots (Holy Saviour) Cathedral, an iconic site for the Armenian Apostolic Church, came under rocket fire on Thursday, as fighting raged between Armenian and Azerbaijani forces over the disputed region of Nagorno-Karabakh.
Armenia blamed its arch-rival, but Azerbaijan said any damage to the church "has nothing to do with the military actions of the Azerbaijani army".
One of the rockets hit the roof of the 19th-century building in the town of Shusha, which is perched on a plateau some 14 kilometres (nine miles) from the regional capital Stepanakert.
"I was arriving at the church when I saw three rockets in the sky. Two went by, but the third hit the roof," said the local groundskeeper.
"My knees are still shaking, it's a miracle I'm not hurt."
Outside the church, jagged pieces of its wooden frame and metal roof lay on the ground.
Inside, rubble was strewn on the floor with pews knocked over or broken. There was broken glass and wood splinters amid the rubble and a thick layer of dust covered everything, getting inside noses and mingling with the lingering smell of explosives.
Overhead was a gaping hole of two to three metres (6 to 9 feet) in the ceiling.
- 'How can you target church?' -
A man lit a candle before making the sign of the cross, another picked up a bible and dusted it off.
"There is no military, nothing strategic here, how can you target a church?" said one visitor, Simeon, who lives nearby.
Witnesses said a handful of worshippers were present when the church was hit, but none was injured and a priest rushed them into a nearby bomb shelter.
Like Stepanakert, Shusha has come under regular fire since the heaviest fighting in years over Karabakh broke out late last month.
The primate of the diocese of Karabakh, Pargev Martirosyan, compared the hitting of the church to the destruction of religious objects carried out by the Islamic State group.
"They are attacking our spiritual values," he told AFP.
The enormous cathedral, built between 1868 and 1887, is of major symbolic importance for Armenians.
It is the seat of the diocese and suffered heavy damage during the 1990s war over the disputed region, when it was used as a storage site for Grad rockets by Azerbaijani forces.
Shusha was a strategic stronghold for Azerbaijani forces during the war. For months in the winter of 1992, rockets rained down on Stepanakert from Shusha, killing thousands.
When separatist forces took control of Shusha and the rest of Karabakh, the cathedral was restored and became an important site for visitors from Armenia and the Armenian diaspora.
"We will rebuild our cathedral, as we have always done throughout our history," Simeon said.
"God will be the judge" of those responsible, he said.
Less than an hour after AFP journalists visited, there was new shelling on the church, Armenia said, leaving several Russian and local journalists wounded.