Eight times winners Al Ahly of Egypt slumped to a shock 1-0 defeat to Young Africans in the first leg of the Caf African Champions League first round tie at the National Stadium in Dar es Salaam.
Skipper Nadir Haroub 'Cannavaro' scored the goal eight minutes before full time.
The home side, with Ugandan stars Emmanuel Okwi, Hamis Kizza and play maker Mrisho Ngasa, dominated play against the reigning champions for most of the match.
Al Ahly, who are seeking a record third consecutive Champions League trophy, have been struggling in their domestic League. They failed to overturn that form in Tanzania and will now have to come from behind in the return leg in Cairo next weekend.
In another big shock, Nigerians Enyimba, champions in 2003 and 2004, lost 2-1 at home to Malians Real Bamako despite going 1-0 up on the stroke of half-time.
Also suffering a surprise first leg defeat were the recent Fifa Club World Cup finalists, Raja Casablanca of Morocco. They fell to a 1-0 loss away to Horoya of Guinea. Keita scoring the home side's goal mid-way through the first half.
In Nairobi, Tunisian giants Esperance secured a 3-2 win away to Gor Mahia at the Nyayo Stadium. Uganda Cranes striker Dan Sserunkuma's scored for Gor Mahia in the 14th minute before Ahmed Akaichi's equaliser. Yannick Ndjeng made it 2-1 for Esperance in the 63rd minute before Haron Shakava levelled for 2-2. It was Haithen Jouwi's 89th minute goal that made the difference, giving Esperance the edge.
Another team from the Cecafa region, Kampala City Council snatched a 2-2 draw away to Nkana Red Devils of Zambia at the Arthur Davies Stadium in Kitwe. Although the Ugandan champions were reduced to 10-men after Tom Masiko's sending off, they held on to secure a draw.
Tony Odur, who scored two goals in the preliminary round against Sudan's El Merreikh, gave KCCA FC the lead in the 25th minute. The home side then earned a penalty in the 35th minute, only to see it saved by Jamal Magoola. Just a minute later, Simon Bwalya lifted home spirits, firing in the equaliser from a well taken Shardreck Musonda pass.
After the break, KCCA had Masiko sent off for a professional foul and Shardreck soon made it 2-1. But Coach George Nsimbe urged his men to push forward as they continued to look for goals, and with 20 minutes remaining, Maybin Chishimba brought down Odur in the box. Brain Majwega converted the penalty to make it 2-2.
Amongst the weekend's big winners were South Africa's Kaizer Chiefs. They made full use of home advantage, defeating Mozambique's Liga Muculmana 4-0.
Elsewhere, Ahly's Egyptian compatriots Zamalek beat Angolans Kabuscorp 1-0 at home. The 1973 African champions Vita of the Democratic Republic of Congo, drew 0-0 away to Dynamos of Zimbabwe and the other DR Congo challengers, TP Mazembe drew 1-1 away to Astres Douala in Cameroon.