Gasquet and Karlovic go through

‘Ed Sheeran, Taylor Swift have been in my locker-room here’ – Tsitsipas excited

Sixth seed Gasquet eased to a 6-3 7-5 win over Pablo Andujar while Karlovic, seeded seventh, came through 7-6 (7/4) 6-3 against Lukas Rosol to move into the last 16 in Doha.

World number one Novak Djokovic and second seed Rafael Nadal begin their campaigns on Tuesday.

Fernando Verdasco hit back from a set down to edge out Teymuraz Gabashvili 4-6 6-3 7-6 (7/4), while there were also first round wins for Simone Bolelli, Ivan Dodig and Dustin Brown.