Britain's Jamie Murray and his partner Bruno Soares cruised into the last four of the ATP Finals by beating Marcelo Melo and Lukasz Kubot.

Melo and Kubot are ranked one and two respectively in the doubles rankings but they were outclassed at London's O2 Arena as Scot Murray and the excellent Soares won 6-2 6-4.

This was an all-or-nothing tie for Murray and Brazilian Soares, who knew success would mean progressing as group winners while defeat would see them eliminated.

Their triumph therefore earns them top spot but arguably a tougher semi-final draw, given they now face defending champions Henri Kontinen and Murray's former partner John Peers on Saturday.

Kontinen lifted the Wimbledon mixed doubles trophy alongside Britain's Heather Watson last year.

Melo and Kubot, meanwhile, go through second in the group and will meet Ryan Harrison and Michael Venus.

There was little unknown between the pairs across the net, with Soares and Melo playing regularly together for Brazil in the Davis Cup while Murray has also partnered Melo in the past.

But, whether placed first or second, Kubot and Melo had already qualified regardless of this result and there was a noticeable difference in the teams' intensities, particularly in the opening set.

Two stinging Soares returns earned him and Murray a break on Melo's serve and then Kubot was broken too when his own lob dropped long on a deciding deuce.

Down 5-0, Melo lashed an overhead long and was fortunate not to catch a ball girl when he irritably whacked a ball in her direction.

Murray and Soares squandered five set points - four on Soares' serve - but finally converted a sixth when a quick exchange at the net ended with Soares sweeping a backhand down the line.

An early break of serve put Murray and Soares in command in the second as well but Murray gifted a break back with a double fault and then had to save three more break points at 3-3.

The threat of a Kubot-Melo comeback was fleeting, however, as Melo double faulted at 5-4 before a Kubot volley landed long to confirm their opponents' victory.