DA CAU SAIGON

Do you mean the sport in which the players kick the ball that looks like a cross between a badminton shuttlecock and a hockey puck while preventing it to fall to the ground?

If that's what you meant, I believe there are two versions of đá cầu. 

One is what I described briefly above, and the other, đá cầu kiểng is the artsy/fancy version in which the players use at least 10 different moves in each play (nose, foot, heel, kicking wings, crossing legs, shoulders, head, back, elbow, and something called Apsara.) 

Think of it as the difference between a regulated basketball game and a performance from the Harlem Globetrotters.  Oh, I'm  just realise you're French -- je suis désolée, vous ne connaissez probablement pas la différence entre les deux versions.

I cannot tell you where the official competitions are held, but I can tell you where to watch the performances of đá cầu kiểng.  Here is what I know:

In Saigon, there are three famous đá cầu kiểng teams:

-  Tiến Thành's performance can be watched at the Saigon Botanical Garden (don't know the time) and 23/9 Park (107 Phạm Ngũ Lão) on Sunday afternoons.  I don't have FB but they do: https://www.facebook.com/%C4%90%E1%BB%9 … 167915094/

- Suối Tiên and Tia Chớp are usually found at Đầm Sen Amusement Park in Q11, Nhà Văn Hóa in Q8, Phú Lâm Park in Q6, and Lê Thị Riêng Park in Q10.

There are a good number of videos on YouTube on đá cầu kiểng.  If that's not what you want, then explain to me in details and I'll do some research and see what I can find.

Amazing ! Thank you very much !
At first I meant the sport you briefly described but I am interested in the other one too.

What do you mean by "Suối Tiên and Tia Chớp" ? Are they people ?

Yes, Suối Tiên and Tia Chớp are the names of the other two teams.  They receive much fewer mentions than Tiến Thành for some reasons.  I've never seen any of the 3 teams' performances so I can't tell you my honest opinion of them.  I have, however, watched the unknown people playing both versions in neighbourhood parks.  The two places I often visit whenever possible are:

- Gia Định Park in Q Phú Nhuận next to Tân Sơn Nhất Airport (many kinds of impromptu local entertainment happen there in the evening, dancing included)

- Lê Văn Tám Park in Q1 (the former French Colonial Mạc Đĩnh Chi Cemetery, Saigon's prestigious answer to Père Lachaise)

Perhaps a visit to Tiến Thành's FB page would help you find the competition schedule for both versions of the game.  Can't help you with that because I gave up FB many years ago.

BTW, Vietnamese often compare đá cầu kiểng to ballet, which is a bit of exaggeration IMO  even though it does look like a combination of sport and performance art.