Third seed Milos Raonic edged past Australia's Nick Kyrgios in a rain-delayed Aegon Championships first round showdown at Queen's Club on Wednesday as new coach John McEnroe watched on.
The big-serving Canadian has hired three-times Wimbledon champion McEnroe to help during the grasscourt season and their partnership got off to a winning start as Raonic won 6-7(5), 6-4, 6-4 to move into the second round.
Rain on Tuesday meant their match had been locked at one set apiece overnight.
On the resumption with the sun shining at the west London club it was level pegging until 4-4 when Kyrgios served two double-faults to gift Raonic a break.
Raonic then battled back from 15-40 down to hold for the win that set up a clash with Czech Jiri Vesely.
"He's been on the court the whole time," Raonic said of four-times Queen's Club champion McEnroe.
"It's been a lot of fun, he's very competitive and it's obviously benefiting me as well."
British wildcard Kyle Edmund surprised eighth seed Gilles Simon of France, winning 6-4, 3-6, 6-1 but his fellow Briton Dan Evans was beaten by Paul-Henri Mathieu.
Top seed Andy Murray, bidding for a fifth title at the prestigious tournament, plays his second round on Thursday against Slovenian-born Briton Aljaz Bedene.
Wawrinka to work with Krajicek for grasscourt season
Should Murray team up with Lendl again? Yes, thinks McEnroe
Australia's No. 1 Kyrgios pulls out of Rio Olympics
Queen's Club: Murray downs Mahut in front of Lendl, Wawrinka out
3 reasons why Murray has best chance to win French Open