Adelaide have maintained their lead at the top of Group E after they played out a cagey 0-0 draw against Bunyodkor at Hindmarsh Stadium on Wednesday
Each side had their fair share of chances on goal but neither was capable of making them count.
Adelaide dominated possession in the first half but could not score, and Bunyodkor carved several good opportunities after the break and looked likely to snatch victory.
The result maintains Adelaide's three-point lead at the top of Group E with Bunyodkor second, pending the result of the other group fixture between Gamba Osaka and Pohang Steelers.
It took 10 minutes until either side settled and found rhythm in a cautious opening.
It was the visitors who threatened first through defender Shorakhmedov Akmal, who pushed high up the ground to deliver a quick in-swinging cross that landed just inches ahead of striker Murzoev Kamoliddin and safely into the hands of Reds captain and goalkeeper Eugene Galekovic.
The hosts struck back two minutes later when Bruce Djite found Iain Ramsay in acres of space out on the left wing with a deft through-ball with the outside of his foot, but the Reds winger rifled his shot over the bar after his first touch let him down.
The returning Dario Vidosic almost opened the scoring in the 17th minute when he turned two Bunyodkor defenders just inside the area, but the 25-year-old's tame left foot shot was comfortably held down low by Uzbekistan custodian Ignatiy Nesterov.
The best chance of the half fell to Adelaide on 21 minutes when the Reds forced a frenetic goalmouth scramble.
After tearing down the right wing and being put through by a delicate pass from Vidosic, Reds full-back Daniel Mullen hit a first-time cross that proved a handful for Bunyodkor keeper Nesterov, who misjudged the flight of the ball as it fell kindly to Ramsay.
However Ramsay's shot was blocked on the line, as was his follow-up effort and one from Djite before Bunyodkor were able to clear.
The last opportunity of the opening half fell to Murzoev, but the Bunyodkor attacker failed to cap off a well-worked one-two with his captain Viktor Karpenko, when the return delivery just glanced past the head of the 25-year-old close to Adelaide's goal.
The second half started much livelier than the first with the Reds straight on attack via Ramsay, who lifted a direct cross to Djite, but the former Gold Coast forward failed to keep his header down.
Socceroo and recent Bunyodkor signing David Carney brought a deafening silence over the Hindmarsh crowd on 51 minutes when he found space inside United's area and struck a thunderous angled effort towards Galekovic's goal.
However, the thumping shot whisked just over the bar.
Reds substitute Iain Fyfe almost made an immediate impact in the 66th minute when Ramsay's up-field free kick found the former Sydney FC man unmarked in the box, but he fired his header straight at Nesterov.
Fyfe tested Nesterov again in the 77th minute with a dipping half-volley strike from distance, but the Bunyodkor keeper was equal to the task once more with a smart stop.
Bunyodkor substitute Salomov could have grabbed all three points late when Karpenko chested down into the midfielder's path, but he dragged his shot narrowly wide of the near post.
Adelaide United 0
Crowd: 7794 at Hindmarsh Stadium