Manchester United's qualification for the knockout phase of the Champions League is still in the balance going into the final round of Group C matches after they were held to a 2-2 draw by Benfica at Old Trafford. Phil Jones's own goal in only the third minute got United off to a disastrous start. However, just as in the reverse fixture at the Estadio da Luz back in September, the Red Devils were on terms by half-time courtesy of a goal from Dimitar Berbatov. Darren Fletcher put United in front on the hour-mark, only for Pablo Aimar to equalise less than two minutes later and maintain the Lisbon side's unbeaten record in all competitions this season. The draw means United were denied their 100th Champions League win under Sir Alex Ferguson's management but, more importantly, they will have to avoid defeat away to Basel in their final group match. Basel, who drew 3-3 at Old Trafford when they visited in September, are just a point behind United and Benfica after winning 3-2 away to group whipping boys Otelul Galati. Although they are unbeaten in Europe this season, three draws in five matches is far from what would usually be expected of the defending Premier League champions, who have reached three of the last four finals. Berbatov was handed only his fifth start of the season as Wayne Rooney was rested, while Ashley Young returned for his first appearance since the 6-1 derby defeat to Manchester City almost a month ago. Oscar Cardozo was the man who opened the scoring when United visited the Estadio da Luz on the opening matchday. The Paraguayan was dropped to the bench for this fixture in favour of the in-form Rodrigo Moreno, but it was one of United's own number who put the visitors ahead. An incisive passing move from Benfica involving Axel Witsel and Aimar allowed Nicolas Gaitan to fire in a low ball from the right flank and Jones - who has never scored a senior goal either for United or former club Blackburn Rovers - beat his own keeper as he tried to cut out the cross. Jones is spared the ignominy of scoring the fastest ever Champions League own goal: that honour goes to Unirea Urziceni's Ricardo Gomes, who put into his own net in only the second minute against Rangers two seasons ago. Benfica continued to press United in all areas of the pitch and offered a real threat every time they came forward. Bruno Cesar flashed a decent effort from range across David de Gea's goal, but the ball flew wide of the far post. United soon began to find more joy going forward as the breathless tempo saw play go from end to end. On the half-hour mark they earned a tangible reward for their 60 per cent of the possession via Berbatov's leveller. Young played a free-kick square and the ball was worked wide to Nani. The Portugal winger clipped an inviting cross for last season's top scorer, who glanced his header past goalkeeper Artur Moraes in typically effortless style. There was more than a hint of offside about the goal, but the officials were sufficiently satisfied that Berbatov had not strayed to award the goal. It was his first Champions League goal for over three years, since netting twice against Celtic in October 2008, and only his second of the season. His first came last month in the Carling Cup win at Aldershot Town. Berbatov almost claimed an assist a minute after scoring when his played a one-two with Young that sent the England man heading for goal, but Artur was off his line quickly to block the effort with his legs on the edge of the box. United came at Benfica again after the break, with Young having a shot blocked and Artur denying Fabio da Silva in a particularly good spell early in the second half. They got their reward on 59 minutes when Benfica failed to clear their lines and Patrice Evra - captain in the absence of the suspended Nemanja Vidic - sent in a cross that caught the defence on the back foot. Fletcher's initial prodded effort was parried by Artur, but the Scotland midfielder reacted quickest to prod home at the second attempt. No sooner had United finished celebrating than Benfica were level again. Bruno Cesar was allowed to cut in from the left flank far too easily and his low ball was blocked half-heartedly by Ferdinand and Aimar rattled home the loose ball from close range. It was the former Valencia playmaker's first Champions League goal for seven years, and just reward for a fine performance in which he was highly influential for the visitors. Aimar then fired over the bar when he should have tested De Gea before drawing a foul from Michael Carrick which saw the United man booked, incurring a suspension for the vital clash in Switzerland in a fortnight's time. Ferguson threw on Javier Hernandez for the last 10 minutes, but it was Berbatov who came closest to scoring for United when he met Fabio's cross with a well-struck volley that flashed the wrong side of the near upright. Rodrigo also went close when he surged into the box and hit the side netting, but a draw was the fair result and sets up an intriguing final round of matches in Group C.