PHILADELPHIA | A fast start by the Philadelphia Flyers gave way to a very nervous ending.</p><p>When it was over, they were still alive and happily facing what many figured was an unlikely return trip to Pittsburgh.</p><p>Joffrey Lupul scored the first of Philadelphia&#8217;s three first-period goals Thursday night as the Flyers extended the Eastern Conference finals for at least one more game with a 4-2 victory over the Penguins.</p><p>&#8220;We have the momentum right now, but we have to come out in Pittsburgh like we did tonight,&#8221; forward Mike Richards said. &#8220;We still have a desperate situation here. We know the mountain that we have to climb. As long as we take it slow and not try to win it in the first 10 minutes and play a full 60, we could have success.&#8221;</p><p>The Penguins&#8217; smooth ride toward the Stanley Cup finals got a bit bumpier and will now include a game five on Sunday.</p><p>Just as they did after taking a 3-0 lead over the New York Rangers in the second round, the Penguins were beaten in game four. Pittsburgh wrapped up that series at home in its next chance, shaking off its only other loss in the playoffs (11-2).</p><p>Jordan Staal scored twice in the third period and got the Penguins close, but Lupul sealed the Flyers&#8217; first win of the series with an empty-netter in the final minute.</p><p>&#8220;They had a good first period, and we didn&#8217;t,&#8221; Penguins captain Sidney Crosby said. &#8220;That was really the difference. We fought hard in the second and third &#8230; but it was just too little, too late.&#8221;</p><p>The Penguins are 7-0 in the playoffs at home and have won 15 straight there.</p><p>&#8220;We want to finish it off,&#8221; Crosby said. &#8220;I don&#8217;t think you go into every series expecting to win four in a row.&#8221;