Felipe Amorim struck a late winner as Port rallied to beat Zhejiang 2-1 in their AFC Champions League Two Group F match in China on Thursday night.
Port are on course to progress to the knockout stage as the victory took the Thai League 1 side to top spot on nine points, two ahead of Singapore's Lion City Sailors. Indonesia's Persib Bandung are third on four while Zhejiang are bottom on three.
Zhejiang took the lead after just seven minutes, thanks to Cheng Jin who dribbled away from Isaac Honny before delivering an inch-perfect cross for Franko Andrijasevic to finish.
Port pulled level 10 minutes after the re-start when Teerasak Poeiphimai provided a perfect through ball for Lonsana Doumbouya, who fended off Wang Yang before shooting past Zhejiang keeper Zhao Bo.
In the last minute of the match, Amorim latched on to Frans Putros' through ball to curl a low shot past Zhao to secure all three points for Port.
Port can seal their knockout stage berth with a win against Persib on Nov 28 while Zhejiang will have little room for error when they face Lion City.
In Group H, Muang Thong United crushed Dynamic Herb Cebu of the Philippines 9-2 in Manila.
Kirins striker Poramet Arjvilai scored a hat-trick to keep his team's hopes of progressing to the knockout stage.
Gino Lettieri's men have five points from four matches. Leaders Jeonbuk have nine points while Selangor are second on seven.
Felicio Brown and Poramet struck in the seventh and 13th minutes respectively to put Muang Thong in front but two goals in three minutes from Guytho Mijland levelled the scores.
However, another goal from Brown as well as a brace from Kakana Khamyok, two more from Poramet plus efforts from Purachet Thodsanit and Songwut Kraikruan saw the Thai League 1 outfit cruise to victory.
Muang Thong will next play away against Malaysia's Selangor on Nov 28 while Cebu will face Jeonbuk.
Stinging Killer Wasps
PT Prachuap host Ratchaburi at their Sam Aoh Stadium today in the Thai League 1 action on Saturday.
Under the guidance of veteran coach Sasom Pobprasert, Prachuap have become one of the strongest teams in the top flight this season.
The Killer Wasps are currently fifth in the standings with 19 points. They will be in confident mood to pick up all three points in their home match on Saturday.