Third seed Juan Martin del Potro opened his Queen's campaign with a clinical 7-5 6-4 victory over Canada's world number 25 Denis Shapovalov.

The 30-year-old, whose season has been interrupted by a knee injury, rarely looked like surrendering his serve.

Shapovalov, 20, has lost in the first round of his past three events and struggled with his ball toss at times.

British number one Kyle Edmund and compatriot Dan Evans are in action later on Wednesday.

Edmund plays top-seeded Greek Stefanos Tsitsipas, while three-time Grand Slam champion Stan Wawrinka is Evans' opponent.

Andy Murray's return to competitive action after five months out and surgery on a career-threatening hip injury has been pushed back until Thursday after Tuesday's rain delays.

He will play alongside Spain's Feliciano Lopez in the doubles.