When archaeology volunteer Margaret Wong pulled large ceramic pieces from the soil at an Empress Place excavation site near the Singapore River, she knew by their weight and smooth texture that they were centuries-old jade green fragments of high quality.
But the enormity of her find sunk in only after Chinese porcelain expert Tai Yew Seng, who had been digging nearby, recognised the fragments as imperial-grade ceramics produced between 1368 and 1398.
The pieces, which formed a 34cm diameter platter, turned out to be one of the most significant artefacts unearthed from the two-month dig that wrapped up last month.
It was carried out by members of the archaeology unit of the Nalanda-Sriwijaya Centre of the Institute of Southeast Asian Studies (Iseas) and volunteers, who shared their experiences with The Sunday Times.
Recalled Ms Wong: "Even though the platter was covered in dirt, I could see that it was valuable and still in relatively good shape. "I felt a thrill digging up an artefact that had lasted 700 years."
Such ceramics were bestowed by China's Emperor Hongwu of the Ming Dynasty only on overseas leaders from countries such as Siam (Thailand) and Champa (Vietnam), according to Dr Tai, a professor at the Nanyang Technological University's Confucius Institute.
This led the team to believe that ancient Singapore, or Temasek as it was known, could have had an established government with a head ruler or chieftain as early as the late 14th century.
Another platter of a similar design dating back to 1381 lies in Syria.
The dig unearthed three tonnes of artefacts - the largest archaeological haul in Singapore in 31 years.
Within the first few days, a team of five Iseas staff and 10 volunteers dug up 150kg worth of artefacts from a 5m by 5m plot.
In comparison, just 303kg of artefacts were dug out from a plot six times larger at the National Art Gallery in 2010.
The Empress Place site is significant because it was where the ancient shoreline once ran.
For decades, Iseas had earmarked it as a potential excavation site.
Archaeologists saw the opportunity to excavate there when they learnt of the Urban Redevelopment Authority's (URA) plans to develop the place into an integrated arts, culture and lifestyle precinct for Singapore's 50th birthday.
Their wish was granted with the help of the National Heritage Board (NHB) after a trial dig to prove the site's richness.
But time was not on their side. Excavators loomed across the 1,000 sq m site - the size of about 10 four-room HDB flats.
Head archaeologist Lim Chen Sian said: "We've never worked on such a tight site and tight schedule. Sixty-tonne machines were moving in slowly and blowtorches were close by. We dug desperately."
Working 13-hour days, seven days a week, some of them barely clocked four hours of sleep.
At one point, as the deadline to return three of the 13 excavation zones loomed, a call for more volunteers was issued. Dozens showed up.
Iseas research officer Aaron Kao, 36, said the sense of urgency was palpable as the team rushed to salvage 700 years of history before it got destroyed. "We felt that we owed it to future generations of Singaporeans," he said.
Volunteer Natalie Khoo, 22, an anthropology and history graduate from the School of the Arts Singapore, said that while some of the work got monotonous, it was "extremely meaningful".
Due to the large volume of artefacts and the complexity of the dig, the team was given a month's extension to continue working on the three zones.
Officials gave the go-ahead after an Iseas report stated that the site was a treasure trove of ancient artefacts.
Still, the team rushed up to the 11th hour. On the last day of the dig, they scrambled to retrieve two timber structures, each measuring about 1m by 1m.
The wood had likely been part of an ancient ship, as its workmanship was typical of the South-east Asian style of shipbuilding. It was the first physical evidence of maritime activity in Temasek.
But a thunderstorm interrupted their excavation for three hours and as night fell, construction workers from the URA's upgrading project set up floodlights for them to retrieve the timber planks.
After the site closed, the core team spent the next three weeks cleaning the artefacts with toothbrushes and water.
At a press briefing last month, NHB said that work on seven of the site's excavation zones has been completed.
The board said the team managed to cover about 70 per cent of the remaining six zones.
Next up for the researchers is to clean, sort and analyse their finds in what is expected to be a three-year task.
So far, 120 large storage containers have been filled with more than a million artefacts and fragments.
They will also be producing a map of the ancient site, which was likely to have been a bazaar.
Sending soil samples for tests could also help pinpoint where sanitation lines ran, for instance. Botanical remains such as shells, seeds and bones could provide an idea of the paleoenvironment of ancient Singapore as well.
NHB, which referred to the excavation as "hitting the archaeological jackpot", will decide if the artefacts will be put into the National Collection and displayed in museums, or at exhibitions.