Bristol’s Natasha Harding spurned a chance in the first minute of the game before Japanese midfielder Ogimi opened the scoring for Chelsea after 13 minutes.
The World Cup winner latched on to a cross from Portuguese striker Ana Borges to head home her fourth league goal of the season.
Chelsea doubled their lead early in the second half when Aluko broke free to shoot across Mary Earps into the corner of the net for her seventh goal in all competitions this term.
Nikki Watts chipped Marie Hourihan to pull a goal back for Bristol on 88 minutes but they were unable to force an equaliser as they dropped two places to seventh in the table.
Manchester City leapfrogged Liverpool in third after a hard-fought 1-0 win over their north-west rivals at the Manchester Regional Arena.
A deflected effort from Krystle Johnston on 17 minutes proved to be the difference between the two sides as City made it six straight wins at home in all competitions.
Liverpool had a good chance to equalise late on but Iceland international Katrin Omarsdottir saw her powerful drive fly just past Karen Bardsley's right-hand post.
The day’s other FA WSL encounter will live long in the memory of Fiona O’Sullivan who scored a last-gasp equaliser on her debut as Notts County Ladies drew 1-1 at Arsenal.
The hosts started well and were ahead after nine minutes when Danielle Carter was brought down by Amy Turner, allowing Casey Stoney to score from the spot.
Jordan Nobbs could have sealed the win for Arsenal late on but was unable to direct her effort on target.
And Arsenal were made to pay for that miss when O’Sullivan met Rachel Corsie’s knock down to fire through a crowded penalty area and into the bottom corner with two minutes to go.