Among the five leaders after three rounds, none was an Elo favourite! The top-rated scored with 3/3 was 2686-rated Bulgarian GM Ivan Cheparinov (who now plays for Georgia), and playing on board 1 in the fourth round, he was the only player to win a fourth consecutive game. That resulted in an interesting round five pairing: black against Veselin Topalov, for whom Cheparinov served as a second for many years.
Topalov heads a group of 13 players a half point behind which includes fellow-2700er Wang Hao, and also young up-and-comers Andrey Esipenko and Parham Maghsoodloo. The latter faces veteran American Grandmaster Gregory Kaidanov, who is an active trainer of young talents himself but seldom plays competitively.

Cheparinov vs Chigaev | Photo: John Saunders
As is typically the case for large open tournaments, most of the favourites prevailed in the early rounds, achieving crushing victories that are rarely possible against their world-class colleagues. For instance, Maxime Vachier-Lagrave outplayed Indonesian IM Irine Sukandar with a slew of powerful pawn pushes in the opening round.
Maxime Vachier-Lagrave speaking with Tania Sachdev | Photo: John Saunders
One notable upset came from the large Indian contingent: WIM Nandhidhaa defeated her fellow countryman Praggnanandhaa, considered one of the greatest talents in the world, in a tactical slug fest.

Praggnanandhaa Rameshbabu | Photo: John Saunders
Moderator Tania Sachdev hosted the Azerbaijani number one Shakhriyar Mamedyarov in the first of the traditional "masterclass" series of lectures in Gibraltar after round two. He showed two interesting games that he won against Loek Van Wely with black and spoke frankly about his career, tournaments and his attitude towards chess.
Both games discussed for replay
Vassily Ivanchuk is a regular in Gibraltar and although the Ukrainian is considered a player who can beat anyone on good days, he is also vulnerable on bad days. He started the tournament in Gibraltar with two wins but stumbled in round four against Mikhail Antipov
White's knight on c6 is a monster, so Ivanchuk eliminated it out of desperation: 35...♜xc6 but after 36.bxc6 ♛xc6+ 37.♕f3 ♛c7 38.♕e4 he resigned as Black is nearly in zugzwang, e.g. 38...b5 39.♜a8 and now there's nothing much for black to do against the white rooks, one of which will soon take over the seventh ranks. E.g. 38...♛c3 (trading queens is also hopeless 39...♛c4 40.♕xc4 bxc4 41.♖c8) 40.♖1a7, etc.

Vassily Ivanchuk is back in 57th place with 2½/4 | Photos: Niki Riga
Topalov is of the same generation as Ivanchuk and while he's not getting invitations to many elite events, he's still dangerous, especially when given the opportunity to unleash a signature exchange sacrifice — as in round three against French GM Fabian Libiszewski, amid a power outage caused by a mishap at the new power facility being constructed in Gibraltar which interrupted play.
Topalov with Tania Sachdev after his third round win
The following round, Topalov gave a veritable master class of his own at the board against Spanish GM Jaime Santos, who prevented the Bulgarian from sacrificing an exchange by taking the opportunity himself in the hopes of holding a worse endgame. But Topalov demonstrated how the rook dominates the knight in this ending.

An older and wiser Topalov? | Photo: Niki Riga
Johannes Fischer contributed reporting