Forward Christine Sinclair registered a brace to lead Portland Thorns FC to a come-from-behind, 2-1 win over Seattle Reign FC in the regular-season finale before a sellout crowd of 3,855 at Starfire Sports Complex in Tukwila, Wash., on Saturday night. After conceding the game's opening goal to Seattle forward Megan Rapinoe in the third minute, Sinclair responded with a goal in each half to record her second brace of the season for Thorns FC. Sinclair netted the game-winning goal in the 83rd minute to finish the regular season tied for the team high with eight goals. Due to Western New York's 2-1 win over the Boston Breakers earlier Saturday, Thorns FC can earn no higher than the third seed in the National Women's Soccer League playoffs. Portland currently has a grasp on third place, but would only drop to fourth if Sky Blue FC defeats the Washington Spirit by three or more goals on Sunday. Depending on Sunday's results, Thorns FC is all but guaranteed to face either Western New York or FC Kansas City in the semifinal round of the playoffs on Saturday, Aug. 24. Sky Blue FC could potentially move into the No. 2 spot if they win by six or more goals. Sinclair, a former University of Portland standout, responded to Rapinoe's go-ahead goal with the equalizer in the eighth minute. Midfielder Allie Long threaded a through ball down the middle of the field for Sinclair and the forward slipped around two Seattle defenders for a one-on-one opportunity against Reign FC goalkeeper Hope Solo. Sinclair took a touch around Solo near the top of the box and delivered a shot into the back of the net to level the score. The assist was Long's third of the season, tying her with midfielder Tobin Heath for second on the team. Forward Danielle Foxhoven nearly put Portland ahead in the 57th minute, but her strike from the top of the penalty box struck the underside of the crossbar and was cleared away from the goal by the Reign FC defense. Thorns FC (11-6-5, 38pts) notched the game-winning goal in the 83rd minute as midfielder/forward Tiffany Weimer looped a pass over the top of the Reign FC defense for Sinclair. The Canadian international outran the Seattle defense, settled the pass and fired low inside the far left post for the game-winning goal. The tally was Sinclair's second game-winning goal inside the final 10 minutes in three appearances against Seattle this season. She netted an 84th-minute penalty kick for the game-winning goal in a 1-0 victory over Seattle on May 25. Portland finished the regular-season with a 4-0-0 record against Reign FC, including a 2-0-0 mark on the road. Reign FC (5-14-3, 18pts), nearly equalizer late in the match as Rapinoe rattled a shot off the left post in the 86th minute and forward Christine Nairn followed with a close-range shot that forced Thorns FC goalkeeper Karina LeBlanc to make a reaction save. LeBlanc came up with another save on a long-range, looping shot from Seattle midfielder Jessica Fishlock in the fourth minute of second-half stoppage time - punching the ball over the crossbar. LeBlanc made seven saves in the win and Sinclair finished with a team-high three shots on goal. Reign FC outshot Portland 18-12 with Rapinoe attempting 12 of Seattle's 18 shots. Following Sunday's final regular-season games, the NWSL playoff pairings and television broadcast information will be announced on Monday.