The 24-year-old, already the winner of sprints at the Tour de Romandie, the Criterium du Dauphine and the Tour de Pologne among others this season, timed his effort perfectly today to secure another win in 3 hours 18min 58sec in the 145.2 kilometres stage from Beihai to Qinzhou held in heavy rain. 

Second place was taken by Dutchman Fabio Jakobsen, while stage one winner Dylan Groenewegen, also from The Netherlands, crossed the line in third.

As a result, Groenewegen retains the overall lead, and the red jersey, by four seconds.

"It was not easy today to get the timing right," the Bora–Hansgrohe rider told Cycling News.

"It was hectic because of the rain, but also because the last two kilometres were on a big road and totally straight which made it difficult.

"Yesterday we messed it up a little, but today everything went perfect."

Australia’s Richie Porte was among those to retire because of the downpour, meaning his time with BMC Racing Team has now come to an end.

The Tour of Guangxi was his last appearance with the team before he is due to join Trek-Segafredo in 2019.

Jhonatan Narvaez from Ecuador was also forced to quit after crashing into a support car.

Despite the weather, four riders including Tousif Mirza from the United Arab Emirates and Alex Dowsett form Britain did manage to attack, and after 25km they had a lead of over two minutes from the rest of the field.

That was as big as their lead got, though, and as the race carried on all of them cracked, with the last rider caught with four kilometres to go.

With the race finishing on such a wide road it was difficult for one sprint team to control the lead out at the end, but Ackermann timed his push perfectly to reach the line first.

Tomorrow's 152.2km third stage is due to see the riders race from Nanning to the Mashan Nongla Scenic Spot.