ASB Classic: Kiwi Michael Venus ousted by Tennys Sandgren

Kiwi Michael Venus' singles campaign at the ASB Classic has come to a swift end, falling to American Tennys Sandgren in straight sets on Monday.

Venus was never in the contest against the defending champion, who rode his blistering serve to a comprehensive 6-4 6-3 win.

Despite the defeat, doubles specialist Venus - who hadn't played singles since 2015 - insisted he took plenty from the experience.

"To be completely honest, that's the most comfortable I've felt on that court playing singles," said Venus afterwards. "I actually felt I could trust my game, I didn't need to play outside my comfort zone.

"Previously, I'd always felt I needed to push it a bit more, but I felt I could play within myself... which was a great feeling.

"There were some errors that cost me at times, but potentially, if I had been playing more singles matches, I may not have made some of those."

The 32-year-old will now turn his attention to the doubles draw, where he and Australian partner John Peer are the tournament's top-ranked pairing. They'll take on New Zealand's Artem Sitak and India's Divij Sharan in their first-round match on Tuesday.

In the final match on centre court, Swedish qualifier Mikael Ymer impressed with an entertaining three-set win over highly favoured American Frances Tiafoe, 6-4 5-7 6-1.

In other results, Brazilian Thiago Monteiro earned the first upset of the men's draw with a 7-6 6-2 win over last year's beaten finalist, NZ-born Brit Cameron Norrie.

Fifth seed Benoit Paire overcome a stern challange from 18-year-old Italian Jannik Sinner to prevail 4-6 6-2 4-6 and book his spot in the next round.

Frenchman Ugo Humbert and Norway's Casper Rudd duelled for more than two hours, before Humbert was able to close out a 7-6 2-6 6-3 win.

Earlier on the opening day, Poland's Hubert Hurkacz defeated Mexico's Lorenzo Sonego 7-5 6-3.