Katie Stengel scored two penalties on her Women’s Super League debut as defending champions Chelsea were stunned by newly promoted Liverpool. Chelsea took the lead when Fran Kirby converted from the penalty spot after Gilly Flaherty collided with Guro Reiten. Sam Kerr saw an effort ruled offside while Liverpool capitalised on their second-half chances to end the Blues’ 13-game unbeaten streak while celebrating their return to the top flight in front of a record 3,006 fans at Prenton Park. Stengel joked she was just trying to avoid embarrassing herself on her Women’s Super League debut. “I told myself don’t miss, please don’t miss, all of these people here will make fun of me if I miss,” the American told Sky Sports. “I was like, I have to change it up, and I got lucky I guess.” The striker said the result was down to her team’s determination, and an invigorating half-time pep talk from the head coach, Matt Beard. “He just reiterated we have to believe in ourselves,” she added. “[He said:]‘We can win this game and it’s just another team out there, another 11 players, and we prepared all pre-season so why not believe in ourselves?’” Chelsea’s head coach, Emma Hayes, was frustrated but insisted she was not worried for her side. “It’s not like in open play they’ve had multiple shots, they’ve just maximised the situations, and for us going forward I don’t think we could hit a barn door today,” she said. “I say it all the time, what’s to be worried about losing a football match. I’m not emotional about it. I think we have to reflect, watch it back and next week’s a new week.” The former Chelsea defender Flaherty got her new side off to an unfortunate start, mistiming her clearance and instead making contact with Reiten to concede a penalty inside the first minute. Kirby stepped up to the spot and sent Rachael Laws the wrong way inside three minutes, her 29th goal in her last 31 starts for the club. Emma Koivisto had a chance to level soon after when the Chelsea keeper Zecira Musovic failed to hold on to a Ceri Holland effort and the Finnish defender pounced on the rebound but sent her effort over the bar. The defending champions dominated throughout the opening exchanges with Lauren James, who earned her first England cap this month, looking especially bright down the right wing. They looked to double their advantage at the 20-minute mark when Kirby sent a long ball over the top to Kerr, who easily fired past Laws from 18 yards but her volleyed effort was immediately ruled offside. Beard’s side were dealt a blow when Leanne Kiernan was forced off, supported by two staff, after she was brought down by Chelsea debutant Kadeisha Buchanan. But Liverpool got the breakthrough they were looking for when Flaherty’s flick-on from a throw-in caught Millie Bright’s arm and was called for handball, and Stengel coolly scored her first WSL goal. Five minutes from time, Stengel broke down the right and into the area, pursued by Buchanan who brought her down with a sliding tackle to set up Stengel for her game-winning second penalty.