Salem Al Dawsari struck lucky with a deflected winner as Al Hilal beat Al Nassr 2-1 in a thrilling Riyadh derby to reach the AFC Champions League final.
Anderson Talisca had headed 10-man Al Nassr level following an early opener from Moussa Marega, but Al Dawsari had the decisive say when his 15-yard strike took a wicked deflection for what proved to be the winning goal in the 71st minute.
At the King Saud University Stadium, three-time competition champions Al Hilal snatched a 17th-minute lead when Marega timed his run perfectly to meet a pass from Bafetimbi Gomis. The striker's powerful shot looped in off defender Abdullah Madu, beating Waleed Ali's dive.
Talisca twice went close to levelling just after the half-hour mark, firstly with a low shot from a tight angle that keeper Abdullah Al-Mayoof scrappily pushed out. Brazilian Talisca then struck a rasping drive from wide on the right flank that grazed the right post.
Al Nassr lost a man in first-half stoppage time, left-back Ali Al Lajami sent off for a wild challenge on Marega, catching the striker dangerously on the shin.
Abderazak Hamdallah had a shot turned wide for a corner by Al Hilal keeper Al-Mayoof, but there was no denying Talisca from the set-piece, as he headed powerfully into the right corner from Abdulfattah Asiri's delivery for a 50th-minute leveller.
Al Dawsari headed wide from a great opportunity for Al Hilal, but he made amends in the 71st minute, albeit with a huge slice of luck. His shot came off Al Nassr captain Madu and nestled in the left corner of the goal, wrong-footing Waleed as a second deflected strike beat the goalkeeper.
Nasser Al-Dawsari hit the bar with a delicate 18-yard chip as Al Nassr chased the leveller that never came, Madu firing six inches wide with almost the last kick of the game.
The second semi-final takes place on Wednesday in Jeonju, as Ulsan Hyundai take on fellow South Korean outfit Pohang Steelers.