USM Alger of Algeria came from behind to win 2-1 at Al Hilal of Sudan on Sunday and stake a strong claim for an African Champions League final place.
The clubs meet again next Saturday in the second leg of the semi-final and a home draw will be enough to take the team from the Algerian capital into the decider for the first time.
Another Sudanese side, Al Merrikh, fared better in the first semi-final 24 hours earlier in another Omdurman stadium by winning 2-1 against TP Mazembe from DR Congo.
Hilal made the perfect start on Sunday, with Mudather 'Careca' Eltaib scoring after just two minutes before a capacity 35,000 crowd at the Al Hilal Stadium in Omdurman.
But USM shrugged off the stamina-sapping 35 degree celsius night-time heat to level 15 minutes later through recent signing Mohamed Amine Aoudia.
Karim Baiteche scored the 67th-minute match-winner with his first goal of the Champions League campaign.
Just before the decisive goal, Hilal squandered a great chance to regain the lead when Brazilian Andrezinho had a penalty saved.
Hilal were runners-up twice when the competition was called the African Champions Cup, while the best previous showing by USM was reaching the 2003 semi-finals.
Algerian outfit Entente Setif won the Champions League last season, edging Vita Club from the Democratic Republic of Congo on away goals after both legs of the final were drawn.
On Saturday, Al Merreikh of Sudan scored 10 minutes from time to grab a 2-1 first-leg lead over TP Mazembe of the Democratic Republic of Congo in their semi-final.
Local star Babeker 'Al Medina' Bakri snatched the winner in front of the 45,000 supporters who filled the Omdurman stadium.
Ghanaian Francis Coffie had put semi-finals debutants Merreikh ahead against four-time African champions Mazembe three minutes before half-time.
Thomas Ulimwengu, one of two Tanzanians in the multi-national line-up of the Congolese outfit, levelled for Mazemebe on 77 minutes.
It was the first goal Merreikh had conceded at home in seven Champions League matches this season, and could prove crucial overall.
A 1-0 victory for Mazembe in the southern mining city of Lubumbashi next Sunday would take them into the final on away goals.
Before Saturday's contest, Merreikh coach Diego Garzitto had admitted he was realising a dream by facing Mazembe with his Sudanese club.
The 65-year-old Italy-born handler had steered DR Congo's Mazembe to victory in the premier African club competition six seasons ago.
The first leg of the other semi-final will also be played in Omdurman with Al Hilal of Sudan hosting USM Alger of Algeria on Sunday at a different stadium.
Drug cheat and leading USM Champions League scorer Mohamed Youcef Belaili has been ruled out of the Hilal tie after receiving a two-year international ban this week.
Belaili, who scored four Confederation of African Football goals this season, tested positive for an unspecified banned substance last month after a group victory over fellow Algerians Mouloudia El Eulma.
USM, whose best previous showing was reaching the 2003 semi-finals, are returning to Omdurman two weeks after losing 1-0 to Merrikh in a group game.
Twice runners-up Hilal are a multi-national squad coached by Tunisian Nabil Kouki and captained by Saif Masawi, a defender with a fondness for scoring goals.
The second legs are scheduled for next weekend in Algiers and Lubumbashi.