MANCHESTER (England) (Agencies) - Wayne Rooney struck a spectacular overhead kick for Manchester United to beat rival Manchester City 2-1 at Old Trafford and strengthen its grip at the top of the Premier League. With his back to goal, England striker Rooney met a right-wing cross from Nani after 77 minutes with a perfectly-timed right-foot strike that flew into the top corner as City goalkeeper Joe Hart stood motionless. Asked if it was his best ever goal, Rooney told Sky Sports later: I think so, yeah. I saw it coming over and I thought why not? Nine times out of 10 they go into the stand. Nani had given Man United a 40th-minute lead when he controlled Ryan Giggs first-time pass before rolling a confident finish past Hart. City equalized after 64 minutes when Shaun Wright-Phillips crossed for fellow substitute Edin Dzeko, whose shot went in off David Silvas back. City deserved to be level with United, having more than held its own for most of the contest. United manager Alex Ferguson sprung a surprise before kickoff by leaving top scorer Dimitar Berbatov on the bench, and playing Rooney on his own up front. City counterpart Roberto Mancini also went for a lone striker in ex-United forward Carlos Tevez and his side should have been ahead after only three minutes when Tevez played in Silva, who shot inches wide of the far post from a close, but tight, angle. Yaya Toure also threatened with a far-post header from a Gareth Barry free-kick, but, by the half-hour mark, Nani was starting to assert his influence and a Darren Fletcher header, from Giggs cross, forced Hart into his first save of the game with 33 minutes gone. Nanis goal, after Rooney had won an aerial challenge in midfield, sent United in at halftime with a 1-0 lead, but City started the second half in committed fashion with a Tevez run threatening and Silva, and Tevez again, shooting tamely at Edwin van der Sar. Rooney, though, had the final say with only his fourth league goal of the season.