Andy Murray began his latest comeback from injury with victory over Liam Broady in the Battle of the Brits exhibition held behind closed doors.
Before his first match in seven months, the 33-year-old Briton played down his chances in Roehampton as he continues to recover from a bruised pelvic bone.
But the three-time Grand Slam champion was relatively sharp and mobile after such a long absence to win 6-2 6-2.
"I moved OK but I find it quite tricky here, the courts are tight," he said.
"It was all right for the first match in seven months. I served pretty well, but I didn't hit the ball that well."
The former world number one, now ranked 129th, was playing for the first time since winning Great Britain's opening match at the Davis Cup finals in November.
He missed the rest of the tournament with the pelvic injury, which he described in February as "unbelievably complex, challenging and difficult".
Murray said these matches at the National Tennis Centre would be where he "found out" where the injury was at and he passed his opening test with a comfortable win over world number 211 Broady.
After breaking to love in the first game, Murray was pegged back at 2-2 before reasserting his control in a dominant opening set.
Working out his fitness level was Murray's primary concern, although he was not completely happy with his game - saying he was not hitting the ball as cleanly as he would like - even when he led by a set and a break.
There were glimpses of his best, however, including a sublime flicked backhand from the baseline on his way to finally taking a 5-2 lead in a 13-minute game where he had seven break points.
Murray sealed victory with a hold to love in the next game, finishing with an ace and roaring 'Come on!' as he clenched his fist in celebration.
"I thought I served well, I was happy with that. I returned well. I made 100% of my backhand returns and 90% of my forehand returns which is very high," said Murray.
"My groundstrokes were not good, my timing was off, my balance a little bit too, but for my first match in that amount of time it was all right, I did the basics well."
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No fans, players collecting their own balls & in-match interviews
The six-day charity event, organised by Jamie Murray, is following strict safety measures.
As well as no fans, there are no ball kids or line judges in order to minimise numbers on court for social distancing purposes, meaning players had to retrieve their own balls and fetch their own towels.
The umpire is assisted by Hawk-Eye cameras instead of line judges, while the players did not change ends.
Shock defeat for Jamie Murray & Skupski, wins for Evans & Edmund
The tournament, featuring singles and doubles, gives top British men's players competition practice before the planned restart of the professional tour in August and will also raise £100,000 for NHS Charities Together.
The eight singles players have been split into two groups, with the semi-finals and final to be played at the end of the week.
In the doubles, two groups of three play each other in a round-robin and the top two from each group will advance to the semi-finals.
In the opening match of the tournament, Jamie Murray and Neal Skupski suffered a shock defeat by Broady and Cameron Norrie.
Regular doubles pairing Murray and Skupski, who reached the US Open semi-finals last year, took the first set against the singles players after securing an early break.
Broady, 26, and Norrie, 24, missed chances of their own before recovering to win the second set and hold on to a fast start in the match tie-break to win 3-6 7-5 11-9.
Dan Evans and Kyle Edmund - Britain's highest-ranked men's players - both started with straight-set wins over James Ward and Jay Clarke.
Teenager Jack Draper, who was the runner-up in the 2018 Wimbledon juniors, pulled out of the tournament with an abdominal injury.
The 18-year-old has been replaced by 24-year-old Ryan Peniston in the singles and by Ward in the doubles.
In the final doubles match of the day, Ward and Edmund beat Peniston and Dom Inglot 7-5 6-3.
Jamie Murray/Neal Skupski 6-3 5-7 9-11 Liam Broady/Cameron Norrie
Kyle Edmund 6-4 6-1 James Ward
Dan Evans 6-3 6-1 Jay Clarke
Andy Murray 6-2 6-2 Liam Broady
James Ward/Kyle Edmund 7-5 6-3 Ryan Peniston/Dom Inglot
Wednesday's order of play (from 13:00 BST)
Liam Broady v James Ward
Joe Salisbury/Jonny O'Mara v Jay Clarke/Dom Inglot
Cameron Norrie v Ryan Peniston
Kyle Edmund v Andy Murray
Liam Broady/Cameron Norrie v Dan Evans/Lloyd Glasspool
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