Frank Lampard's side drew 0-0 with Valencia in their opening game before crushing Krasnodar 4-0 last week and got off to a fine start against their Ligue 1 opponents, with Werner slotting home from the spot in the 10th minute after he had been fouled by Dalbert.
The Brazilian was then dismissed after receiving a second yellow card for handball in the area four minutes before the interval, Werner stepping up to slam home his seventh goal of the season in all competitions.
Tammy Abraham added a third five minutes into the second half as Chelsea moved onto seven points at the summit of Group E, level with Sevilla.
Chelsea were given the opportunity to take an early lead when Dalbert tripped Werner in the penalty area, the German following up his penalty against Krasnodar last week with another successful spot-kick that proved too powerful for Alfred Gomis.
Dalbert's dismal first half went from bad to worse shortly before the interval when he received a second booking for handling Abraham's shot inside the penalty area, referee Felix Zwayer reaching the decision after consulting the pitchside monitor.
Werner stepped up again and lashed into the roof of Gomis' net to double Chelsea's advantage.
Hakim Ziyech blazed a half-volley over from eight yards shortly after the restart before Abraham turned home Reece James' cross inside the six-yard area to put the Blues 3-0 up.
Gomis denied substitute Olivier Giroud late on as Chelsea ultimately failed to add further gloss to what was the most comfortable of victories.
What does it mean? Blues barely break into a sweat
Champions League games are not meant to be this easy. Rennes might well point to the dismissal of Dalbert as the turning point, but Lampard's men were already cruising at that stage. They restricted Julien Stephan's side to just two shots on target and enjoyed 57 per cent possession in a dominant display.
The result means Chelsea have now suffered just one defeat in their last 16 Champions League group games at home.
James on relentless form
James was superb at right-back for Chelsea, his wonderful cross for Abraham's goal one of six he delivered during an all-action display. He also gained possession a team-high eight times and completed 92.3 per cent of his passes.
Dalbert's torrid 40 minutes
The on-loan Inter defender endured a tumultuous first half, giving away two penalties and receiving a red card. The fact he completed 100 per cent of his 17 passes will be of no comfort at all.