Makupa OCS was punched in the abdomen when supporters of the two politicians clashed during the meeting at Tononoka Grounds.
The cop was assaulted when he led officers from the GSU and Rapid Response Unit in quelling the chaos that disrupted the celebrations.
Chaos started when Jubilee and Awiti’s supporters ganged up against Joho’s followers. The clashing groups booed and hurled insults at one another.
Mombasa county commissioner Evans Achoki was forced to cut short the President's speech following the altercation that lasted nearly 30 minutes.
Achoki's frantic call to the crowd to observe a moment of silence for those killed in the Karai, Naivasha accident was not heeded to.
Awiti has declared interest in Mombasa governor seat, currently held by Joho, during the 2017 election.
During the Mashujaa Day celebration, the two camps shouted at each other while some youth were roughed up by police.
Awiti and Joho have also traded barbs in the past with the MP accusing the governor of mismanaging and "driving the county to the dogs".
Joho has defended his development track record and blamed underdevelopment in the county on the national government saying the latter has starved the devolved unit of funds.
The Nyali MP, who arrived at the Monday's celebration on a tuktuk, exuded confidence that he will be elected the next Mombasa governor.
Joho has also said that he will retain his seat after the August 8 polls.
-Source