Former world number one Andy Murray beat Germany's Alexander Zverev to advance to the Qatar Open quarter-finals and added to his exciting start to the season.
Following a compelling three-hour battle in Qatar, Britain's Murray dug deep into his physical and mental reserves to prevail 7-6 (7-5) 2-6 7-5.
In a year in which all four of Murray's victories have occurred under dramatic circumstances, it was yet another brave victory for him.
"I managed to stay strong, keep fighting and get the break at the end," said Murray.
"I would like to win the matches quicker but Alex is a top player and a great competitor, who always fights until the end. In the third set, I was hanging on and he was making better chances."
In the first round of the Australian Open, he defeated Italian 13th seed Matteo Berrettini by surviving a match point. In his subsequent match, against Thanasi Kokkinakis, he overcame a two-set deficit to win at four in the morning.
He defeated Italy's Lorenzo Sonego on Monday in Doha by saving three match points and winning the tie-break in the last set.
Also, British number one Cameron Norrie defeated Brazilian Thiago Monteiro 7-5, 7-5 at the Rio Open in Brazil to go to the quarterfinals.
Norrie created 21 break points in a two-and-a-half hour marathon, of which 16 were saved, and on his sixth match point, he tied Bolivia's Hugo Dellien for a spot in the last eight.