Liverpool - Everton slumped to back-to-back Premier League defeats for the first time this season as Stoke City came away with a 1-0 win at Goodison Park on Friday.
Having been humbled 3-1 at Southampton last Saturday, Everton were hoping to bounce back and make up ground on the top five, but a 38th minute penalty from Bojan Krkic sealed all three points for coach Mark Hughes on a return to one of his former clubs.
Bojan was fouled by James McCarthy and then stepped up to rifle home the spot-kick, right-footed into the bottom right-hand corner.
A number of injury delays in a physical first-half on a miserably cold, wet day on Merseyside led to almost 10 minutes being added on, but Stoke showed no sign of relinquishing their advantage, despite Everton having the lion's share of possession.
Martinez's side remained unable to show much intensity after the break, as Ross Barkley struck wide and Romelu Lukaku shot tamely to goalkeeper Asmir Begovic.
There was more tough tackling before the end, though, with Gareth Barry being booked for clattering Steven Nzonzi and Stoke substitute Charlie Adam receiving the same punishment for bringing down Kevin Mirallas.
The result brought Everton's five-match unbeaten home run to an end and stemmed the slide for Stoke, who had taken just four points from a possible 18 in their previous six games.
Steven Naismith had a header cleared off the line, Kevin Mirallas passed up a decent-looking chance to equalise and Leighton Baines' drive was parried by Asmir Begovic, but Everton struggled overall to create much against a solid Stoke outfit.
In an inconsistent season, Everton have now lost three times at home and won only one of their last six league games.
Roberto Martinez's men slipped a place to 12th, with Stoke - following only their second victory in seven matches - replacing them in 11th.