Physical optimization for timing closure for an integrated circuit includes processing a circuit design at least partially through a design flow to a late stage of the design flow. Using a processor, a baseline delay is calculated for each of a plurality of paths of the circuit design. A slack for each of the plurality of paths is determined. Physical optimization further includes selecting a path of the circuit design that meets a selection criterion according, at least in part, to the slack of the path, applying, using the processor, a physical optimization to the selected path resulting in an optimized path, and calculating a delay of the optimized path. The optimized path is incorporated into the circuit design only responsive to determining that the delay of the optimized path is less than the baseline delay of the selected path.