Niemann and Lewis each shot three-under-69 on Friday to reach 10-under-134. Troy Merritt (68), Chris Kirk (68) and Max Homa (65) were a setback.
First round leader Davis Thompson was one of eight players two strokes back. The 22-year-old Thompson had a 1-over-73, a day after he equaled a Detroit golf club record with a 63.
The wind picked up considerably during the second round with gusts up to 25 km / h that knocked hats off the heads and made the relatively short and easy track more challenging.
Defending Champion Bryson DeChambeau, sixth on the world rankings, expressed his frustrations about the unpredictable wind and his shaky game throughout his round.
He missed the cut at 1 under 143, after an opening 72 with a 71.
The surprising split with Tucker also gave Brooks Koepka more feed for jabs via social media, which declared on Thursday on Twitter as ‘day of appreciation’.
Nearly two weeks ago, the 2020 U.S. Open champion put the same nine-hole nine-hole lead to 26th with a crash. Despite being part of flawed fields, DeChambeau equaled a 19th place finish at the Travelers’ Championship last week and was unable to reach the result in Detroit.
Patrick Reed, who was one of only two players in the field to be in the top-10, was also on the leaderboard at 3 bottom after rounds of 69 and 72.
Master Champion Hideki Matsuyama withdrew on Friday after testing positive for COVID-19. The PGA Tour does not test players who have been fully vaccinated.
At least 35 players had to withdraw due to a positive test and Matsuyama is the fifth in the middle of a tournament since the test program began last June. The last PGA Tour tournament, excluding the majors, is the Barbasol Championship on July 15-18.
The Associated Press contributed to this report.