Terracina - German Pascal Ackermann won a sprint finish in the pouring rain in the Giro d'Italia fifth stage on Wednesday, claiming his second victory in this year's race as former winner Tom Dumoulin withdrew a day after picking up a knee injury in a crash.

Bora-Hansgrohe rider Ackermann edged Colombia's Fernando Gaviria of UAE Team Emirates.

The final nine kilometres did not have an impact on the overall times because they were neutralised because of poor weather conditions.

Slovenia's Primoz Roglic, riding for Jumbo-Visma, holds a 35sec overall race lead after the 140km stage ahead of Britain's Simon Yates of Mitchelton-Scott with Italy's Vincenzo Nibali of Bahrain-Merida third at 39sec.

"It was scary all day under the rain," said 25-year-old Ackermann, competing in his first Giro, and who has five wins so far this season.

"It was a two-time sprint today. I had to brake at 250 metres to go but luckily Gaviria became the perfect lead out man for me. I had a lot of power in the end."

Belgian Louis Vervaeke had led a long breakaway after the race started in Frascati, to the southeast of Rome, before being caught 23km from the line.

It was a particularly miserable day for Dutch rider Dumoulin, the 2017 Giro winner, who had started among the race favourites after finishing runner-up last year to Britain's Chris Froome.

Dumoulin also came second at the Tour de France in 2018 and won the 2017 world championships time-trial.

The 28-year-old was 56th, 4min 30sec behind Roglic, after coming down in a mass crash seven kilometres from the finish in stage four.

The Sunweb rider had insisted he would tough out the stage and signed in to begin the race, but once he started pedalling realised he could not continue.

"For me it's terrible," said Dumoulin.

"Months and weeks of preparation and dedication went into this Giro and in one moment it's over."

"It's not how I wanted it to go of course, but it is how it is," he continued.

"I don't know how bad the injury is, we only know that nothing is broken and it will probably just be swollen for a few days, but we have to see.

"For now I will just rest and see how it goes."

Thursday's sixth stage covers 238km from Cassino to San Giovanni Rotondo, in the Puglia region of south-western Italy, with the riders hitting the Coppa Casarinelle climb with a 4.4km gradient 15km from the finish line.

Results and standings after Wednesday's fifth stage of the Giro d'Italia, a 140km run from Frascati to Terracina:

Stage

1. Pascal Ackermann (GER/BOR) 3hr 15min 44sec, 2. Fernando Gaviria (COL/UAE) s.t., 3. Arnaud Demare (FRA/FDJ) s.t., 4. Caleb Ewan (AUS/LOT) s.t., 5. Matteo Moschetti (ITA/TRE) s.t., 6. Ryan Gibbons (RSA/DDT) s.t., 7. Paolo Simion (ITA/BAR) s.t., 8. Yenthe Biermans (BEL/KAT) s.t., 9. Giovanni Lonardi (ITA/NIP) s.t., 10. Manuel Belletti (ITA/AND) s.t.

Selected:

38. Bob Jungels (LUX/DEC) s.t., 39. Mikel Landa (ESP/MOV) s.t., 49. Vincenzo Nibali (ITA/BAH) s.t., 61. Primoz Roglic (SLO/JUM) s.t., 73. Miguel Angel Lopez (COL/AST) s.t., 75. Simon Yates (GBR/MIT) s.t., 76. Tao Geoghegan Hart (GBR/INE) s.t.

Retired: Tom Dumoulin (NED/SUN), Jelle Vanendert (BEL/LOT)

Did not start: Kristijan Koren (SLO/BAH)

Overall standings

1. Primoz Roglic (SLO/JUM) 19hr 35min 04sec, 2. Simon Yates (GBR/MIT) 35, 3. Vincenzo Nibali (ITA/BAH) 39, 4. Miguel Angel Lopez (COL/AST) 44, 5. Diego Ulissi (ITA/UAE) 44, 6. Rafal Majka (POL/BOR) 49, 7. Bauke Mollema (NED/TRE) 55, 8. Damiano Caruso (ITA/BAH) 56, 9. Bob Jungels (LUX/DEC) 1:02, 10. Davide Formolo (ITA/BOR) 1:06

Selected:

19. Pascal Ackermann (GER/BOR) 1:37, 22. Mikel Landa (ESP/MOV) 1:49, 31. Caleb Ewan (AUS/LOT) 2:26