Former world number one Andy Murray earned a second-round clash with Casper Ruud at the San Diego Open after easing past lucky loser Denis Kudla in straight sets.

Murray – a three-time grand slam champion – defeated Kudla 6-3 6-2 in just over an hour, winning an outstanding 28 of 31 (90 per cent) first-serve points on Tuesday.

The 34-year-old Murray was also on top on return, converting three of four break-point opportunities against Kudla, to complete a comprehensive display.

Murray – currently ranked 116th in the world – will face second seed Ruud next at the ATP 250 tournament.

Elsewhere, Grigor Dimitrov was made to work for his 6-3 1-6 7-5 victory over Hungarian Marton Fucsovics.

Former world number three Dimitrov triumphed in two hours, seven minutes, confirming a spot in the second round, where he will face US Open semi-finalist Felix Auger-Aliassime.

Diego Schwartzman – the sixth seed – progressed with a 6-2 6-3 win over Italian qualifier Federico Gaio.

Young American Sebastian Korda beat Tommy Paul 6-3 5-7 6-1 in more than two hours, while ninth seed Lorenzo Sonego, Cameron Norrie and Lloyd Harris were also victorious.