Former champion Gilles Simon was a surprise first-round casualty at the Sydney International on Tuesday as he was beaten by Jared Donaldson.

Simon's fortunes appeared to be on the up after he put a forgettable 2017 behind him by winning the Maharashtra Open title in Pune on Sunday. However, the Frenchman – who won the Sydney title in 2011 – came crashing back down to earth as Donaldson completed a 6-1 6-4 win.

Simon was not the only shock exit as eighth seed Mischa Zverev also bowed out, the German beaten 7-5 6-3 by Leonardo Mayer. Fernando Verdasco's Australian Open preparations were also cut short as he fell at the hands of Alex de Minaur, the home favourite cruising through in straight sets.

Benoit Paire joins the teenager in round two after coming from a set down to beat Aljaz Bedene, but Tuesday's remaining matches were victims of the rain. Heavy showers saw lengthy delays to the schedule on day five, meaning Ricardas Berankis' match with fifth seed Adrian Mannarino, and Fabio Fognini versus Alexandr Dolgopolov will take place on Wednesday.

Chung Hyeon's rise looks set to continue after he booked a second-round spot at the Auckland Open, the South Korean battling past Tennys Sandgren in three sets.

Chung's stock has been high since lifting the Next Gen ATP Finals in November, and he showed his character by saving nine of the 12 break points against him to set up a clash with fourth seed John Isner.

Tuesday also saw sixth seed Pablo Cuevas start his season with a straight-sets win over Taro Daniel, while there were also victories for Steve Johnson and Jiri Vesely.