Australian Open: Andy Murray finds his focus after being prepared to withdraw

Sears collapsed on Rod Laver Arena on Saturday while he watched Ana Ivanovic, whom he coaches, and was rushed straight to a Melbourne hospital.

Murray visited Sears twice, on Saturday night and Sunday morning, before the 58-year-old was released and given the all-clear to fly home.

The British No 1 recovered his focus to beat Australia’s Bernard Tomic 6-4 6-4 7-6 (7/4) but said he would not have played if the news on Sears had been less positive.

“It was tough, obviously it depended on Nigel’s health,” said Murray.

“If the news was not positive then ‘no’ there was absolutely no chance I would have kept playing.

“It was a tough few days. It certainly wasn’t straightforward. I’m just glad that he’s on his way home now and can be back with his family.”

Murray has been busy with off-court issues throughout his time in Australia, with his wife Kim heavily pregnant and expected to give birth in the middle of February.

Sears’s illness, however, was as concerning as it was unexpected for the 28-year-old, who admits he carried his anxiety into the match against Tomic. “When I woke up, I felt quite drained, quite tired.

“As the day went on and I decided to play, I started to focus a little bit better but definitely on the court I was more emotional than normal.

“I was talking to myself after every single point almost from the first point through to the last, which was obviously not ideal.

“That uses up a lot of energy. Again, just that makes you sort of more kind of up and down throughout the match, as well.

“Certainly, I was trying to just concentrate on the match when I was out there but like I said, it’s been a hard, hard few days.

“Hopefully, it gets better in the next few days. I just can’t believe something like that happened a few days ago. It’s shocking. Nige is an unbelievably fit guy. Very, very scary.”

Murray was certainly not at his rhythmic best against Tomic, who broke the Briton four times during a topsy-turvy contest.

The world No 2, however, delivered at the crucial moments to secure a quarter-final meeting with Spain’s eighth seed David Ferrer, who enjoyed a straight sets win over John Isner.

“I didn’t think it was that straightforward. It was a tricky match,” said Murray. “I got up a break I think in all of the sets. Each time, he obviously got it back. So there were quite a few momentum shifts in all of the sets.

“Luckily, he missed a few easy forehands in the tie-break, and that helped me out in the breaker. It helped me get it done in straight sets.”

French Open champion Stan Wawrinka revealed how a 10-day illness contributed to his fourth-round defeat to Milos Raonic.

Wawrinka came from two sets down but could not win the decider as Raonic won 6-4 6-3 5-7 4-6 6-3.

Raonic reached the semi-finals at Wimbledon in 2014 and he has struck form again in Australia, out-powering Wawrinka with 82 winners and 24 aces.

Raonic, who faces Frenchman Gael Monfils, is following through on an impressive start to the season which saw him beat Roger Federer earlier this month.

Monfils beat Russian Andrey Kuznetsov in four sets but injured a hand when attempting an acrobatic dive.