MANCHESTER, England, Dec 7 (Reuters) - Manchester United's ( MANU ) weakness from set pieces was exploited again as they fell to a 3-2 Premier League defeat by Nottingham Forest at Old Trafford on Saturday, continuing a rocky start to the reign of new head coach Ruben Amorim.

Having conceded from two corners to Arsenal in a 2-0 defeat in midweek, United went behind from another corner within two minutes as Forest defender Nikola Milenkovic headed home before Danish striker Rasmus Hojlund levelled in the 18th minute.

United started the second half equally badly as goalkeeper Andre Onana allowed Morgan Gibbs-White's bouncing effort to slip past him two minutes in and was then beaten by a looping Chris Wood header from a Gibbs-White cross seven minutes later.

Bruno Fernandes pulled one back with a blistering finish from just outside the box in the 61st but United could not find an equaliser. They stay 13th on 19 points, while Forest's first win at Old Trafford in 30 years moves them up to fifth on 25.