There have been four races so far in the 2020/21 season and Friedrich has won them all.
On Sunday the reigning Olympic, World, and World Cup champion Friedrich teamed up with push athlete Alexander Schüller to make it four-in-a-row, setting a new track record at 49.19 seconds.
He improved on his own previous record a day earlier in Sigulda when he won World Cup No.3 in 49.31s with Thorsten Margis pushing.
On Saturday there were celebrations for local hero Oskars Kibermanis pushed by Matiss Miknis, as the Latvians finished in second place just 0.10 seconds behind Friedrich. Third place went to Simon Friedli/Gregory Jones from Switzerland, the European Championship silver medallists last winter.
Sunday saw 22-year-old Michael Vogt take second behind Friedrich, his best IBSF World Cup result so far, Sandro Michel doing a fine job shoving.
World Championships runner-up Johannes Lochner finished third with Christian Rasp, 0.53 seconds behind in fourth.
Friedrich now has an incredible record at Sigulda winning six of his seven races the Latvian venue.
Laura Nolte completes German sweep
With Friedrich's double in Sigulda, 22-year-old 2016 Youth Olympics Champion Laura Nolte made it a bobsleigh clean sweep for Germany over the weekend.
Nolte won the season's second 2-woman bobsleigh race of the IBSF World Cup 2020/2021 putting down the fastest times on both runs with Leonie Fiebig pushing.
Nolte defeated Olympic Champion Mariama Jamanka who finished in second with Vanessa Mark while World Championships runner-up Kim Kalicki with Ann-Christin Strack also claimed silver after there was a tie for second place.
The two German duos were 0.24 seconds behind their team-mates Nolte/Fiebig, making it an all-German podium.
Janine Flock wins skeleton in Sigulda
Austria's super slider retained her 100% record at Sigulda Part 2 with two scorching runs that set track records in both heats.
Last season's overall runner-up lowered her own mark from last week to 51.46 seconds.
European Champion Elena Nikitina from Russia, who has happy memories here in Sigulda from when she won her second European Championship title here in February 2020, finished second just 0.65 seconds off Flock's time.
World Champion Tina Hermann (GER) and Dutch athlete Kimberley Bos (both 0.80 seconds behind) tied for third place.
Reigning World Cup title holder Jacqueline Lölling's difficult start to the season continues as she came seventh, following an eighth place finish at the World Cup opener in Sigulda.
Better news for 2016 Youth Olympics champion Ashleigh Pittaway from Great Britain who finished eighth, her best World Cup result so far.
Skeleton: Dukurs brothers delight
Home fans had double the reason to celebrate as Martins Dukurs won World Cup No.2 just one week after his opening victory in Sigulda, and he was joined on the podium by his brother Tomass Dukurs who finished second.
Martins (37) won the season's second race, making it 2/2 World Cup victories, and he did it in style setting a new track record at 49.45 seconds.
The six-time world champion improved on his own track record from last season by almost half a second.
Tomass Dukurs (39) was just 0.19 seconds behind his younger brother.
Britain's Marcus Wyatt stepped onto his first podium after he finished just 0.94 seconds behind the elder of the Dukurs, becoming the first British skeleton athlete on a World Cup podium since Dominic Parsons in Calgary, Canada, in November 2013.
Not a great day for World Champion Christopher Grotheer (GER), third after the first run, as he finished seventh in Sigulda.
And it was a lucky escape for Russia's Alexander Tretiakov, the 2014 Olympic Champion avoided a crash but dropped from third to tenth between the first and second run.