Pawn endings can be tricky, even for GMs.
Hou Yifan blundered in a pawn ending against Giri
http://www.chessgames.com/perl/chessgame?gid=1908491
A few years ago (2013) Hou Yifan also blundered in a pawn ending, in the same Petroff defense opening, against Carlsen.
http://www.chessgames.com/perl/chessgame?gid=1813974
Also at TataSteelChess, Jobava blundering into a pawn ending in 2015
http://www.chessgames.com/perl/chessgame?gid=1782562
And in 2014 a pawn ending could have been played better :
http://www.chessgames.com/perl/chessgame?gid=1744587
Hou Yifan blundered in a pawn ending against Giri
http://www.chessgames.com/perl/chessgame?gid=1908491
A few years ago (2013) Hou Yifan also blundered in a pawn ending, in the same Petroff defense opening, against Carlsen.
http://www.chessgames.com/perl/chessgame?gid=1813974
Also at TataSteelChess, Jobava blundering into a pawn ending in 2015
http://www.chessgames.com/perl/chessgame?gid=1782562
And in 2014 a pawn ending could have been played better :
http://www.chessgames.com/perl/chessgame?gid=1744587