Bafetimbi Gomis scored at both ends as Al-Hilal recovered from an early setback at Jassim Bin Hamad Stadium to beat 10-man Al Sadd 4-1 in Tuesday's AFC Champions League semi-final first leg.
Al Sadd had won five successive home games in the competition and were in front 14 minutes in when Gomis inadvertently turned a low cross into his own net.
But Gomis redeemed himself by deservedly drawing the visitors level and Xavi's men were dealt a further blow before half-time as Abdelkarim Hassan was dismissed, the Qatari defender shown quickfire yellows for kicking the ball away after a strong challenge and then his poor reaction to being booked.
Al-Hilal made the man advantage count by taking control of the tie, with Ali Albulayhi ghosting in at the back post to put them in front on the brink of the interval.
Gomis struck again with an hour played and Mohammad Al-Shalhoub converted from close range seven minutes later to give Razvan Lucescu's side a huge advantage ahead of the return match on October 22.