It was the veteran's 200th clean sheet in the Premier League and Wenger paid tribute.
Over his years of service for the Blues, Cech collected several records in quick fashion before passing the torch to young keeper Thibaut Courtois in his last season at Stamford Bridge, leaving SW6 as a Premier League and League Cup victor to then join Arsenal in the summer of 2015.
But when Troy Deeney stepped up to take the spot kick, Cech made a fine save that saw him become the first goalkeeper in Premier League history to keep 200 clean sheets.
However, his right-footed shot from the centre of the box was saved.
Arsenal are sixth in the table with 48 points, 12 behind the last Champions League qualifying spot. "I believe that I like him as a player and when you get negative statements you have to deal with it". "You can not be a football player without pride".More news: Trump Signals A Change To A Key Detail In His Proposed Tariffs
They beat AC Milan 2-0 in the first leg of their last 16 tie on Thursday night and host the Italians in the return leg later this week.
Massimiliano Allegri is willing to leave Juventus to take over at Arsenal if Arsene Wenger leaves the club this summer, according to reports in the British media.
"In one week we got from hell to heaven", Wenger said. "Second half, we suffered a bit but spirit was high and we stick together".
"We can discuss how the team plays or something else, but I find that the criticisms that fall on Arsene on a personal level are hard to accept".
"Watford came back strong in the second half but overall it was a convincing win and an important one".
"Maybe it doesn't come across as being loud on the pitch - and you don't see it as much - but we do speak when things aren't going as well as planned".
Wenger added: "There is a lot of negativity. But it is a bit of understanding because of the week we have had". "We have still some work to do, but we are on a good way".