Nick Kyrgios has lost to former world No.3 and one-time sparring partner Stan Wawrinka in the opening round of the ATP Masters 1000 event in Canada.
Kyrgios, who last week withdrew from a tournament in Washington DC due to an ongoing injury, raced through the opening set but was unable to win the big points when they mattered most to go down 1-6 7-5 7-5.
The world No.17 showed glimpses of his best, however, unleashing a brutal forehand winner that even three-time grand slam champion Wawrinka applauded.
"What can you say?" Sky Sports commentator Mark Petchey said.
It was one of 44 winners Kyrgios struck to Wawrinka's 35. The Swiss had 23 unforced errors to 34 for Kyrgios.
The Australian said his hip injury was still an issue but we would play doubles with Ivan Dodig later on Tuesday.
"It's great to see him back," Kyrgios said of Wawrinka.
"Matches like can give him positives ... I can't take any positives from that for me."
Kyrgios was at the centre of controversy in Canada three years ago when he alleged that fellow Australian Thanasi Kokkinakis had slept with Wawrinka's girlfriend, Donna Vekic.
Wawrinka said in the lead-up to Tuesday's match that the relationship between him and Kyrgios was "not an issue".
"It's true that we had a clinker," he told Tennis World, "but time has gone since when we lift the spirits. Facing him on Tuesday is not an issue at all."
Wawrinka will face Marton Fucsovics in the second round with a possible clash with Rafael Nadal looming after that match.
Wimbledon champion Novak Djokovic, whose original opponent Hyeon Chung withdrew with a back injury, was too good for Bosnian lucky loser Mirza Basic, winning 6-3 7-6 (7-3).
"I've never played Basic. I've known him, I've practised with him, but I've never played an official match so definitely not easy to find a rhythm from the beginning of the match," Djokovic said.
"There were frustrations at times but that means I care."
There were first-round wins on Tuesday for 14th-seeded Italian Fabio Fognini, Sam Querrey, Ryan Harrison, Frances Tiafoe, Stefanos Tsitsipas, Karen Khachanov, Robin Haase, Canadian wild card Felix Auger Aliassime and qualifier Evgeny Donskoy.
